initial changes in ast, parser, and scanner for casting
fixed merge conflicts
fixed some errors, still working toward casts
removed yacc files
parsing/scanning of cast works
added variable cast and failing tests
working toward SAST
closes #78
add and, or, and clarify null
closes #75
closes #72
closes #76
update scoping for renaming vars
fixed merge conflicts
progress on bool cast
Merge branch 'master' into casting

Conflicts:
	compiler/tests/parsing/decl_bool.rapid
better errors
add cast functions for the nullable primitives
passes semantic checking. also updated compiler test
code generation almost works, go errors as of now