While running make check, I noticed that it was actually using
the virsh binary from my system, in /usr/bin/virsh, and not the
one that was just compiled.  This is actually caused by a bug
in Makefile.am, where we didn't update the PATH to include tools.

While here, I also updated all of the scripts to properly define
the srcdir, abs_top_srcdir, and abs_top_builddir environment
variables.  This is required if you want to be able to run the
tests standalone (i.e. ./test instead of from make check).  I've
tested this on both RHEL-5 and Fedora-10 machines, and make check
works on both, as does running the individual tests by hand.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* src/util.c (fread_file_lim): New function.
(__virFileReadAll): Use fread_file_lim, rather than requiring
that stat.st_size provide a usable file size.
* tests/read-non-seekable: New test, for the above.
* tests/Makefile.am (test_scripts): Add read-non-seekable.
* tests/test-lib.sh (mkfifo_or_skip_): New helper function.

* tests/Makefile.am (test_scripts): Add vcpupin.
(EXTRA_DIST): Add test-lib.sh.
* tests/test-lib.sh: Testing framework, from coreutils.
* tests/vcpupin: New file.
* build-aux/mktempd: New file, from gnulib.
* bootstrap: Add posix-shell and mktempd to the list of imported modules.
* gnulib/m4/posix-shell.m4: New file, from gnulib.