Adds a new `_print` function to print strings without coloring or
other stuff added by the `_msg` function. It's used for the usage
message, letting it be translated.
The usage messages have been split into one-line strings, and added
back to the tomb.pot and *.po files.
Issues:
`gettext -s - "$2"` prints the -, instead of getting the desired effect
The custom expansion missed repeated variables in a single string
Some string fixes
