re-org
re-org
re-org, nullptr check before push in exec_variable
re-org, nullptr check before push in exec_variable
re-org
Merge branch 'master' of https://github.com/ahebert/Cx

Conflicts:
	examples/exec_test.cx
	include/exec.h
	include/std_members.h
	lib/common.cpp
	lib/error.cpp
	lib/std_members.cpp
	lib/symtable.cpp
	lib/types.cpp
	src/additive.cpp
	src/assign.cpp
	src/buffer.cpp
	src/common.cpp
	src/complist.cpp
	src/do.cpp
	src/error.cpp
	src/exec.cpp
	src/expression.cpp
	src/factor.cpp
	src/function.cpp
	src/icode.cpp
	src/init_list.cpp
	src/logical.cpp
	src/malloc.cpp
	src/multiplicative.cpp
	src/parse_declarations.cpp
	src/parse_directive.cpp
	src/parse_expression.cpp
	src/parse_routine1.cpp
	src/parse_routine2.cpp
	src/parse_statement.cpp
	src/parse_type1.cpp
	src/parse_type2.cpp
	src/parser.cpp
	src/relational.cpp
	src/scanner.cpp
	src/statment.cpp
	src/std_members.cpp
	src/symtable.cpp
	src/tknnum.cpp
	src/tknstrsp.cpp
	src/tknword.cpp
	src/tracer.cpp
	src/types.cpp
	src/unary.cpp
	src/while.cpp
	stdlib/lib/io/io.cpp