Remove AC_CHECK_HEADER_STDBOOL

AC_CHECK_HEADER_STDBOOL is not supported in ubuntu precise which is used
by travis-ci.
Merge pull request #24 from czchen/bugfix/travis-ci

Remove AC_CHECK_HEADER_STDBOOL
comment regexp symbol
use ck_assert instead of ck_assert_int_gt
check NULL pointer
Fix gnu c compiler error when the variable is the same
-ggdb when debug mode is enable (--enable-debug)
enable -ggdb when building test files
Allocation fixes
Fix memory allocation
fix tests
delete config.h since it's autogenerated
Add travis status image
delete config.h.in
Fix placeholder finder
more slug compile test
Add failing tests for {idx:\d{3}}-{idy:\d{3}} pattern
remove debug print
Add coveralls.io support
Merge pull request #25 from czchen/feature/coveralls

Add coveralls.io support