T1686 - First patch to allow LilyPond Initialisation to use Guile V2 if required. (issue 6849088)

[dak]

http://codereview.appspot.com/6849088/diff/1/lily/main.cc
File lily/main.cc (right):

http://codereview.appspot.com/6849088/diff/1/lily/main.cc#newcode65
lily/main.cc:65: int guile_major_version = 2;
I don't think it makes sense to even define a guile_major_version since
the executable will only work with the version it has been compiled
with.  So there is no point in having a run-time decision criterion
available.

http://codereview.appspot.com/6849088/diff/1/lily/main.cc#newcode296
lily/main.cc:296: /*
You have quite a few commits that "just" add comments to existing
functions.  I think it would make sense to commit these improvements of
existing code as a separate commit to staging.  No point really to have
them go through a review unless you are unsure whether some comment is
correct (adding an incorrect comment obviously is not an improvement).

If those are interspersed with other material in some commit, you can
use

git checkout -p commit-id

to selectively pick out material from a given commit (in a different
branch), then do git commit to make a commit from the picked changes.

http://codereview.appspot.com/6849088/