Refactored various functions to operate in-place.

Numerous prominent functions (e.g., :remove_string_ansi(),
:remove_string_text_matching_glob()) now behaves in an in-place manner, which is
to say operating directly on the contents of the passed variable. Also, color
functionality has been somewhat streamlined. Sadly, in the wake of an admittedly
poorly thought-out bevy of prior exception handling changes, such functionality
has a good way yet to go. (And we shall go.)