gtester: implemented logic to handle failing tests, self tests, and validate XML...

gtester: implemented logic to handle failing tests, self tests, and validate XML reports.

* gtester.c: terminate when tests failed. keep XML valid when test cases fail.
restart test binaries when tests fail, resuming after the last processed test.
support --gtester-selftest to run gtester itself as test program.
support --test-arg=<arg> to pass args along to test programs. added
main_selftest() which does a simplistic fixture test. fail if exit
code of test programs is not 0.

* gtestframework.h: added G_TEST_LOG_SKIP_CASE test log message type.

* gtestframework.c: support --GTestSkipCount=<n> to skip a number of tests.

* tests/Makefile.am: added test-report: for demonstration purposes.
added gtester-xmllint-check: and hooked it up into check:, this rule calls
gtester as test program, running it's selftest, and then uses xmllint to
validate the generate XML test log file.

svn path=/trunk/; revision=5904