[Lilypond-auto] Issue 2604 in lilypond: LILYPOND_BUILD_DIR

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Maintainability

New issue 2604 by address@hidden: LILYPOND_BUILD_DIR
http://code.google.com/p/lilypond/issues/detail?id=2604

We should define a
  LILYPOND_BUILD_DIR
environment var in lilydev.

This needs to be:
- in the list of lilydev-building instructions
- eventually included in the next version of lilydev, but that's a  
lower-priority issue.
- somewhere so that experienced developers not using lilydev can find it

It should be:
- used in the CG quick-start guide
- used elsewhere in the CG

Bonus points for
- making relevant scripts use it