major refactoring (enable isolated multiple ffi_state which holds isolated macro and source-tree cache)
implement selective cdef
support begin and end __ of C keywords (it treated as __ less token)
fix injection problem that same cdef injected twice
fix import test
remove ldconfig -v option from travis_install.sh (debug purpose, no more used)
Merge pull request #5 from umegaya/umegaya/feature/selective_cdef

Umegaya/feature/selective cdef travis says it seems to be good, I will merge this