[eclipse-pmc] Request PMC approval for changes in Resource Filters API

[Szymon Brandys <Szymon.Brandys@xxxxxxxxxx>]

GOALS/BENEFITS:

A new Resource Filters API was added during 3.6. I found some minor issues,
which should be fixed.

1. CompoundFileInfoMatcher#filterTypes should be renamed to #matchers.
The structure in the compound matchers keeps matchers, not filters.

2. CompoundFileInfoMatcher#instantiate should not be API.
FilterDescriptor#createFilter() is non-API (on purpose), so overriding
#instantiate does not make sense.

3. AbstractFileInfoMatcher#initialize should throw CoreException, otherwise
there is no way to indicate that initialization failed.

The only user of it inside the SDK is UI. However UI changes would be
released along with Resource Filters API changes.

ASSOCIATED BUGS:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=305542

RISKS:
Low to None. If there are any consumers for 1) and 3) it is very easy to
adjust their code to these changes.
For 2), overriding this method does not make sense. There was no intention
to make this method public.

PERFORMANCE IMPACT:
None.

Let me know if you have any questions.
--
Szymon Brandys