support c++ exception
fix compile error
add cxx_abi travis test
fix compile error of min/max macro
move jmpbuf_id to generated file
name c++ abi build
use g++ to link
revert wrong build_config.rb
wrap scope with do {} while()
define __STDC_* macros in y.tab.cxx too
define mrbconfs on all compiler
clear exc_catched before jumping to L_RAISE
add const to char* to pacify warnings for string litral to char* conversion
wrap function prototype by extern "C"