Replace 'INCLUDE' with 'AM_CPPFLAGS' in Makefile.am
and do some required modifications

Remove the old 'AC_SUBST'
Change 'AM_CPPFLAGS' to 'DEDAULT_CPPFLAGS'
Merge pull request #116 from hiunnhue/master

Replace 'INCLUDE' with 'AM_CPPFLAGS'

Closed #68, #114