Add zopectl.command for reindexing

[tschorr]

This adds a zopectl.command entry point for reindexing Solr. I needed this because when calling @@solr-maintenance/reindex in the browser, reindexing stopped after ~ 7500 documents, with still ~90000 documents to go. I guess it is the browser that eventually closes the connection.
The PR also fixes a problem in _get_site with recent Zope versions (args has changed).

[tisto]

@tschorr travis build is broken. Would you mind checking? I would merge the reindex_solr script right away. The _get_site fix would need some more explanation and testing I guess. Maybe it would be better to separate those two issues. BTW: Please update the changelog.

[tschorr]

So first, Travis: The build terminated while trying to download the Solr tarball. This should be unrelated to my changes. I would restart the build, but I am not allowed to do so.

[tisto]

I re-ran the build. It is green but there is an unreported code violation. We need to fix the travis conf...

[tschorr]

As for the _get_site fix, I'm still googling for where and when the change occured that causes the bug in the original _get_site version.
Maybe a likely candidate is
plone/plone.recipe.zope2instance@7c52c42 , but I'm not 100% sure.
It happens in Zope2.Startup.zopectl, starting at line 374 in run_entrypoints/go. Here the comment says "remove -c and add command name as sys.argv[0]". But when I put in a debugger, I can see that sys.argv has already 3 elements and '-c' is the middle one. What gets removed is the last element, resulting in ['-c', 'solr_reindex|clear', 'site_name'] being passed to the entry point.
I'm using Zope2-2.13.22, plone.recipe.zope2instance-4.2.15.

Bottom line, without the fix, none of the entry points will work, and my suggestion would be to leave it in this PR. Also, the fix should be save to use with older versions Zope2/plone.recipe.zope2instance.
I'll google some more and will add a comment in the code when I update the changelog.

+1 for more tests, but in this case I'm not yet sure where to start...

[tschorr]

I finally decided to not rely on positional arguments and rather use a flag to pass the site id. It looks like plone.recipe.zope2instance should override Zope.Startup.zopectl.ZopeCmd's run_entrypoint method. This is also the place where tests should be added.
I have added a comment in _get_site and updated the changelog.

[tisto]

@tschorr if we rely on argparse, don't we have to add it to the dependencies (Python 2.7)?

[tschorr]

argparse is part of the Python standard library since the first Python 2.7 release:
http://svn.python.org/projects/python/tags/r27/Misc/NEWS (you can search for "6247")
So I'd say it's not necessary to add it to the dependencies.

[tisto]

Ok, I guess we have to decide if we drop Python 2.6 support or add it as a dependency.

[tschorr]

Added, with a comment (for easier removal later).