Remove build machinery for bundled dependencies.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 89e6125e..c5e90750 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,7 +36,7 @@ endif()
 if(PACKAGE)
   # this needs to be set before project() is called
   set(CMAKE_OSX_DEPLOYMENT_TARGET 10.12)
-  set(ASSETS ON) # necessary for packaging
+  set(ASSETS OFF) # necessary for packaging
   message(STATUS "Building Extempore for binary distribution (assets directory will be downloaded)")
 endif()
 
@@ -134,71 +134,6 @@ else()
   message(FATAL_ERROR "Sorry, Extempore isn't supported on this platform - macOS, Linux & Windows only.")
 endif()
 
-########
-# PCRE #
-########
-
-# current in-tree PCRE version: 8.38
-
-add_library(pcre STATIC
-  # headers
-  src/pcre/config.h
-  src/pcre/pcre.h
-  src/pcre/ucp.h
-  # source files
-  src/pcre/pcre_chartables.c
-  src/pcre/pcre_compile.c
-  src/pcre/pcre_exec.c
-  src/pcre/pcre_globals.c
-  src/pcre/pcre_internal.h
-  src/pcre/pcre_newline.c
-  src/pcre/pcre_tables.c
-  )
-
-target_compile_definitions(pcre
-  PRIVATE -DHAVE_CONFIG_H
-  )
-
-if(PACKAGE)
-  target_compile_options(pcre
-    PRIVATE -mtune=generic)
-endif()
-
-#############
-# portaudio #
-#############
-
-add_library(portaudio STATIC
-  src/portaudio/src/common/pa_allocation.c
-  src/portaudio/src/common/pa_allocation.h
-  src/portaudio/src/common/pa_converters.c
-  src/portaudio/src/common/pa_converters.h
-  src/portaudio/src/common/pa_cpuload.c
-  src/portaudio/src/common/pa_cpuload.h
-  src/portaudio/src/common/pa_debugprint.c
-  src/portaudio/src/common/pa_debugprint.h
-  src/portaudio/src/common/pa_dither.c
-  src/portaudio/src/common/pa_dither.h
-  src/portaudio/src/common/pa_endianness.h
-  src/portaudio/src/common/pa_front.c
-  src/portaudio/src/common/pa_hostapi.h
-  src/portaudio/src/common/pa_memorybarrier.h
-  src/portaudio/src/common/pa_process.c
-  src/portaudio/src/common/pa_process.h
-  src/portaudio/src/common/pa_ringbuffer.c
-  src/portaudio/src/common/pa_ringbuffer.h
-  src/portaudio/src/common/pa_stream.c
-  src/portaudio/src/common/pa_stream.h
-  src/portaudio/src/common/pa_trace.c
-  src/portaudio/src/common/pa_trace.h
-  src/portaudio/src/common/pa_types.h
-  src/portaudio/src/common/pa_util.h
-  )
-
-target_include_directories(portaudio
-  PRIVATE src/portaudio/include
-  PRIVATE src/portaudio/src/common)
-
 # platform-specific
 
 if(APPLE)
@@ -224,25 +159,8 @@ if(APPLE)
 
 elseif(UNIX AND NOT APPLE)
   # use ALSA on Linux
-  target_sources(portaudio
-    PRIVATE src/portaudio/src/hostapi/alsa/pa_linux_alsa.c
-    PRIVATE src/portaudio/src/os/unix/pa_unix_hostapis.c
-    PRIVATE src/portaudio/src/os/unix/pa_unix_util.c
-    )
-  target_include_directories(portaudio
-    PRIVATE src/portaudio/src/os/unix)
-  target_compile_definitions(portaudio
-    PRIVATE -DPA_USE_ALSA)
-  target_link_libraries(portaudio
-    PRIVATE asound)
 
   if(JACK)
-    target_sources(portaudio
-      PRIVATE src/portaudio/src/hostapi/jack/pa_jack.c)
-    target_compile_definitions(portaudio
-      PRIVATE -DPA_USE_JACK)
-    target_link_libraries(portaudio
-      PRIVATE jack)
   endif()
 
 elseif(WIN32)
@@ -292,8 +210,6 @@ if(ASIO)
 endif()
 
 if(PACKAGE)
-  target_compile_options(portaudio
-    PRIVATE -mtune=generic)
 endif()
 
 ##############
@@ -411,8 +327,6 @@ endif()
 
 # dependencies
 
-add_dependencies(extempore pcre portaudio)
-
 if(BUILD_LLVM)
   if(WIN32)
     add_dependencies(extempore LLVM-install)
@@ -553,7 +467,7 @@ else()
   install(TARGETS extempore
     RUNTIME
     DESTINATION ".")
-  install(DIRECTORY assets runtime libs examples tests
+  install(DIRECTORY runtime libs examples
     DESTINATION "."
     PATTERN ".DS_Store" EXCLUDE)
 endif()
r</td></tr>
<tr><td><span title='2016-10-08 23:32:19 +0300'>2016-10-08</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=824f7de882d61d1922a36c86bc2be447c683d6f9'>gnu: freeipmi: Update to 1.5.4.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2016-08-11 13:20:16 +0300'>2016-08-11</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=f9c646886a8b61ec043c19eb801c3d97d9f7cfa3'>gnu: freeimpi: Update to 1.5.3.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2016-05-25 09:13:13 +0300'>2016-05-25</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=19d6248634a81247a9e14f8f61e485d62327bea1'>gnu: freeipmi: Update to 1.5.2.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2015-12-02 20:32:30 +0200'>2015-12-02</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=7e006b68990d45cae28f86d884b298c5f6221ad5'>gnu: freeipmpi: Update to 1.5.1.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2015-10-30 13:12:44 +0200'>2015-10-30</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=cd4cb1b597f3d42ade7e71dac718a41070ce6acc'>gnu: freeipmi: Update to 1.4.11.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2015-10-21 18:00:23 +0200'>2015-10-21</span></td><td><a href='/guix/commit/gnu/packages/freeipmi.scm?id=641dd73dc847e2643727ffc0501de5d1a0946291'>gnu: freeipmi: Update to 1.4.10.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>