Purity: don't look for library dependencies (of the form `-lfoo') in
/lib and /usr/lib.  Likewise, when searching for included Makefiles,
don't look in /usr/include and friends.

Borrowed from similar patch for GNU Make and adjusted for Remake.

--- remake-4.3+dbg-1.5/src/read.c.orig	2020-03-14 17:06:16.000000000 -0500
+++ remake-4.3+dbg-1.5/src/read.c	2020-07-31 22:34:03.862383862 -0500
@@ -104,7 +104,7 @@
 # define INCLUDEDIR "."
 #endif
     INCLUDEDIR,
-#ifndef _AMIGA
+#if 0
     "/usr/gnu/include",
     "/usr/local/include",
     "/usr/include",
--- remake-4.3+dbg-1.5/src/remake.c.orig	2020-03-14 17:06:16.000000000 -0500
+++ remake-4.3+dbg-1.5/src/remake.c	2020-07-31 22:34:26.798330508 -0500
@@ -1665,8 +1665,10 @@
 {
   static const char *dirs[] =
     {
+#if 0
       "/lib",
       "/usr/lib",
+#endif
 #if defined(WINDOWS32) && !defined(LIBDIR)
 /*
  * This is completely up to the user at product install time. Just define
='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=648085dab6c614926c47c6d4f6b8d12d82587724'>refs</a><a class='active' href='/guix/log/doc/images/shepherd-graph.dot'>log</a><a href='/guix/tree/doc/images/shepherd-graph.dot?id=648085dab6c614926c47c6d4f6b8d12d82587724'>tree</a><a href='/guix/commit/doc/images/shepherd-graph.dot?id=648085dab6c614926c47c6d4f6b8d12d82587724'>commit</a><a href='/guix/diff/doc/images/shepherd-graph.dot?id=648085dab6c614926c47c6d4f6b8d12d82587724'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/doc/images/shepherd-graph.dot'>
<input type='hidden' name='id' value='648085dab6c614926c47c6d4f6b8d12d82587724'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=648085dab6c614926c47c6d4f6b8d12d82587724'>root</a>/<a href='/guix/log/doc?id=648085dab6c614926c47c6d4f6b8d12d82587724'>doc</a>/<a href='/guix/log/doc/images?id=648085dab6c614926c47c6d4f6b8d12d82587724'>images</a>/<a href='/guix/log/doc/images/shepherd-graph.dot?id=648085dab6c614926c47c6d4f6b8d12d82587724'>shepherd-graph.dot</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/doc/images/shepherd-graph.dot?id=648085dab6c614926c47c6d4f6b8d12d82587724&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>