[[ AssertCmd ]] Implementation of new 'assert' command.
[[ AssertCmd ]] Fixed parsing issues involving unquoted literals.
Merge branch 'develop' into feature-assert

Conflicts:
	engine/src/cmds.cpp
	engine/src/lextable.cpp
	engine/src/parsedef.h
	engine/src/parseerrors.h
Merge branch 'feature-assert' of https://github.com/runrevmark/livecode into feature-assert
[[ Assert ]] Added release note.
Merge branch 'feature-assert' into develop