Many changes to Patchy

[John Mandereau]

Hi guys,

After lots of testing, debugging, and commits editions cycles, I've
pushed many changes to Patchy in lilypond-extra master branch.  Most
changes regard Patchy on a server and patches testing.

These changes are expected to make existing Patchy setups work at
least as well as before; on the contrary, please complain by replying
to this message, or send a report on this list.

Among the new features, which you can have a glance at in the git log:
* optionally build the docs when testing patches (in the section
[compiling], set the option "patch_test_build_docs" to "yes", and if
you remember to clean out test results often or have a TB of free
space, you can set "patch_test_copy_docs" to "yes" too),
* limit resources used by the build; for adjusting settings in
[self_limits] and [runner_limits] configuration sections, see
http://docs.python.org/library/resource.html and "man setrlimit",
* more configurable email notifications.

Hopefully enjoy!
Best,
John