meta-policy for the CG

[Graham Percival]

We have a new CG chapter for administration:
http://lilypond.org/doc/v2.13/Documentation/contributor/administrative-policies

In particular, it lays out the responsibilities for the Meisters (Bug,
Doc, Translation, and Frog), and gives the "completion status" of the
CG chapters.  This basically means whether you should bother asking
for opinions+review before making changes in git.

Do not change (other than spelling mistakes) without discussion:

    * Introduction to contributing
    * Working with source code
    * Issues

Please dump info in an appropriate @section within these manuals, but
discuss any large-scale reorganization:

    * Compiling
    * Documentation work
    * Regression tests
    * Programming work

Totally disorganized; do whatever the mao you want:

    * Website work
    * LSR work
    * Release work
    * Administrative policies


Cheers,
- Graham