Normal vs. Standalone FreeBASIC

When built from source, FreeBASIC can be configured for and installed in 
one of these two different setups:

Normal build (default)
Standalone build
Normal directory layout:
   * bin/
      * fbc.exe
      * [<target>-]ld.exe
      * other tools for native/cross compilation...
   * include/
      * freebasic/
         * fbgfx.bi
         * other headers...
   * lib/
      * freebasic/
         * <target>/
            * libfb.a
            * other libraries...
Standalone directory layout:
   * bin/
      * <target>/
         * ld.exe
         * other tools...
   * inc/
      * fbgfx.bi
      * other headers...
   * lib/
      * <target>/
         * libfb.a
         * other libraries...
   * fbc.exe
Differences to the standalone build:

   * fbc is located in bin/, like other programs
   * looks for includes in include/freebasic/, instead of inc/, to cleanly 
     separate FB headers from system headers
   * looks for its own libraries in lib/freebasic/ instead of lib/, to 
     cleanly separate FB libraries from system libraries
   * looks for binutils/gcc 1) in bin/ and 2) by relying on PATH
   * looks for crt/gcc libraries 1) in lib/freebasic/ and 2) by running "
     gcc -print-file-name=..."
   * -target option accepts system triplets such as "i686-pc-linux-gnu" or 
     "x86_64-w64-mingw32"
   * the target name given to the -target option is prepended to the 
     gcc/binutils program names when cross-compiling
   * compatible with the standard /usr or /usr/local directories
   * typically used for the FB-linux release
   * uses windres from binutils to compile win32 resource scripts

This makes the normal FB build integrate with GNU/Linux distributions and 
other Unix-like systems pretty well, allows fbc to be installed into MinGW 
or DJGPP trees next to gcc, and allows fbc to work with binutils/gcc 
cross-compiling toolchains.
Differences to the normal build:

   * the fbc binary is located at the toplevel, not inside bin/
   * looks for tools inside bin/<target>/, i.e. it uses bin/<target>
     /ld.exe instead of bin/[<target>-]ld.exe
   * looks for FB includes in inc/, not in include/freebasic/
   * looks for libraries in lib/, not in lib/freebasic/
   * does not try to rely on PATH and use system tools
   * does not try to query gcc to find files
   * -target only accepts simple FB target names, no system triplets
   * typically used for the FB-dos and FB-win32 releases
   * uses GoRC to compile win32 resource scripts

The standalone build is intended to be used for self-contained 
installations such as the traditional FB-win32 and FB-dos releases. It also 
allows adding fbc to the PATH, without having to add the whole bin/ 
directory.

