tabr 0.4.1 release

• Fixed pitch_freq documentation error.
• Fixed bug relating to multiple labels to as_music.
• Fixed bug where lyrics were not parsed correctly when rests present for music object rendering functions.
• Fixed bug where an explicitly added bar inside quotes failed due to a line break inside the string.
• Added better support for a variety of line breaks.
  • The bar argument to phrase (and associated functions) is now NULL by default, or character, rather than simply TRUE or FALSE. If a string is provided, it is interpreted as LilyPond bar notation. E.g., bar = "|" adds the LilyPond syntax \bar "|" to the end of a phrase.
  • If only a bar check is desired, TRUE is still accepted and will insert a bar check only rather than a literal bar. FALSE is treated as NULL for completeness.
• Handle extra whitespace in pc and pn.
• Fixed bug where final note in a scale was droppped by scale_note.
• Unit test updates.
• Documentation updates.