Remove options `noemptylinemacro` and `nolinemacro`; add option `linemacro`

This only concerns the situation when `savemacro` is also passed.

When `linemacro` is passed, the macro expanded .mod file is the same as before

When `linemacro` is not passed, the macro expanded .mod file is equivalent to what it was before when both `noemptylinemacro` and `nolinemacro` were passed.

closes #44
closes #45