working on INDIRECT_POST_INC/DEC
working on INDIRECT INC/DEC
compile pre inc/dec for local var, upvalue and property
compile post inc/dec operayors for local var, upvalue and property
working on +=
+=, -= and etc operators have been implemented for local var, upvalue var and property
improve error detection
fix a.b.c++
Merge branch 'master' of https://github.com/unitpoint/objectscript into unitpoint-master

Conflicts:
	src/objectscript.cpp