Merged in the squid-amake branch from sourceforge.

Merged in the squid-amake branch from sourceforge.

Due to the different policy regarding the autotool generated files, the Makefile.in files
for cvs.squid-cache.org have been updated in place, and the extra autotool support files
- such as depcomp - added. These should be filtered from sourceforge.

Also of particular note:
* new make targets dist-all - creates two distribution tarballs, one .tar.gz, one .tar.bz2.
  These do not include all the source files - things like the test suite are deliberately
  left out.
* distcheck - creates a .tar.gz dist tarball and confirms that it builds with the default
  options.
* the module files - lru/heap/ufs/basic etc are now libraries - liblru.a etc.
* The module files are build from the directory above, ie to build just liblru cd to
  src/repl, and type make liblru.a. The benefit to this is that parallelised makes get
  better efficiency, as they don't have to serialise each stub node.