First release of ly/tablature.ly

First release of ly/tablature.ly 

Additional tunings in scm/output-lib.scm (additional tunings) 

Additional function in scm/parser-clef.scm to add clefs at runtime

[joeneeman, 2009-06-23 18:31:53]

I don't know much about the issues here, but here's a review, fwiw. Of course,
you'll need to update the docs also (and a regression test or 2 would be nice).

http://codereview.appspot.com/67174/diff/1/2
File ly/tablature.ly (right):

http://codereview.appspot.com/67174/diff/1/2#newcode205
Line 205: tabFullNotation = {
Why not create a new context, FullTabVoice, or something like that? Do you
expect people to use \tabFullNotation mid-piece?

http://codereview.appspot.com/67174/diff/1/2#newcode237
Line 237: \layout {
It seems to me that we have 3 versions of tablature now: the "default" version
in engraver-init.ly, the version that appears if the user includes
"tablature.ly" and the "full" version that the user gets by including
tablature.ly and using the tabFullNotation. Is there a reason for keeping the
old versions in engraver-init.ly? Perhaps we should scrap them altogether and
require that the user include tablature.ly in order to get tabs.