proposed patch: Bug 69609 - registrymodification.xcu in presets folder not implemented in newly created profiles.

[Justin Luth]

I am working on Bug 69609 - allowing /presets/registrymodification.xcu
to be incorporated into a new user profile.  This would be a really easy
way for a system administrator to deliver a customized default
configuration to his users.  A proposed patch has been added to the bug
report.
https://bugs.freedesktop.org/show_bug.cgi?id=69609

By far, the best way to manage default settings is to write a
configuration extension.  However, that is a HUGE, daunting step for
your average sysadmin to take.  Documentation is sparse, debugging
ability is non-existent, and intimate knowledge of XML in general and
LibreOffice configuration in particular is required.   The barrier to
entry is extremely high.  (I wrote it off as too difficult initially, a
co-worker implemented it successfully 'by luck', and even after that I
still failed to successfully modify our extension to add another change
and gave up after a few hours.  I finally got it right the last time I
tried.)

A popular, simpler alternative is to copy a pre-configured profile
over-top of the existing one in the user's home directory, but that kind
of scripting is annoying and unreliable (or using an /etc/skel or
Default User profile for brand-new users - but that doesn't catch
existing users).

This bug fix tries to find the middle ground approach. The barrier to
entry in this case is extremely minimal.  An administrator only needs to
know about the existence of the .../presets folder.  Then they can
simply copy a "known good" profile into that location.  They don't need
to identify the specific XML entries for the settings they want to
change, and they don't need to mess with individual's profiles or
scripting.  (The big downside compared to a config extension is that
changes can't be made after a profile already exists, but perhaps you
could get away with just deleting individual's profiles, and then they
start with a fresh one automatically.)

To lower the barrier even further (so a sysadmin doesn't have to know
how to properly "prune" his registrymodifications.xcu template file),
I'm trying to build in some "sysprep" type of exclusions that don't
apply to a default profile (like document history/recovery, personal
information, etc.). 

Questions:
1.)  Are there any objections to implementing this into LibreOffice
4.5?  How about 4.4.1?  Essentially this "middle ground" solution was
there already - except that it just happened not to work because of the
blank, in-memory version of registrymodifications.xcu.

2.)  What other config keys ought to be excluded in a generic profile? 
(keys which don't already exist in the "migration from a previous
version" exclusions - the code already reads that list and excludes them.)

3.)  Any advice/critique in general is welcome.   This is my first time
to consider submitting any significant code changes.

Thanks,
Justin