Allowing -H to extract all defined header fields

[Michael Haynie]

The attached small patch has the effect of causing 'lilypond -H all' to 
write out every field that appears in the header block of the score 
being processed.  This is useful for constructing various types of 
indexes, such as the metrical index, composer index, and tune index 
common in hymnals.

Code making heavy use of this feature will appear in a separate patch, 
since it deserves some discussion.

2006-04-09  Michael Haynie  <address@hidden>

        * scm/backend-library.scm (output-scopes): Support extracting all
        defined header fields via '-H all'

patch
Description: Binary data