Add manual submission data to plugin when scraping

Summary:
... Github-sourced plugins. Particularly, ensure we update category and tags
from submissions.

Still TODO: use category and tag data for vim.org-sourced plugins too

Test Plan:
- ran `make review_submissions`, added some plugins and noted their category+tags
- ran `PYTHONPATH=. python tools/scrape.py -s github-plugins 5` to scrape those newly-added manual plugins
- looked at each newly added plugin on web UI, ensured category and tags were correctly added
- tested adding tags from web UI to ensure that still worked

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D219
Bandaid hack: restart RethinkDB (and server) daily

Summary:
... because RethinkDB has been dying
every few days for some reason.  I have tried updating RethinkDB's patch
version, but the problem still seems to be there. There are no errors output to
RethinkDB's log file when this happens.  This may or may not have to do with
Rethinkdb gobbling up too much memory.  For now, we'll just restart the server
and rethinkdb daily -- these restarts are graceful and quick and so shouldn't
be too disruptive.

In the future I should try experimenting with changing Rethinkdb
cache sizes (though it looks like Rethinkdb is already using the minimum
possible memory), or just ask on #rethinkdb.

Test Plan:
- ran script on server
- it worked, things restarted correctly
- hit vimawesome.com to ensure it still works
- saw memory usage drop after restart according to `htop`

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D221
Add logrotate file; install on deploy

Summary: This allows us to more easily look at the log files of a particular day.

Test Plan:
This logrotate config file has already been running on the server for more than
a week now. See $HOME/logs/cron/archive.

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D223
Add and use vim.org submission data

Summary:
We used to just ignore vim.org submissions because we'd scrape them anyway.
However, user submissions include category and tags data that we can update
plugin rows with, which is what this revision does.

Test Plan:
- ran `make review_plugins`
- reviewed two vim.org plugins and accepted them
- ran `PYTHONPATH=. python tools/scrape/scrape.py -s vim.org`
- checked that the accepted submitted plugins have their category and tags correctly set

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D220
Add manual submission data to plugin when scraping

Summary:
... Github-sourced plugins. Particularly, ensure we update category and tags
from submissions.

Still TODO: use category and tag data for vim.org-sourced plugins too

Test Plan:
- ran `make review_submissions`, added some plugins and noted their category+tags
- ran `PYTHONPATH=. python tools/scrape.py -s github-plugins 5` to scrape those newly-added manual plugins
- looked at each newly added plugin on web UI, ensured category and tags were correctly added
- tested adding tags from web UI to ensure that still worked

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D219

Conflicts:
	tools/scrape/github.py
Increase server cache timeouts

Summary:
Now that we're restarting and warming up the server every 24 hours, might as
well increase cache timeouts so that we're always serving from cache, and that
cache is regenerated every 24 hours during the restart.

Test Plan:
- hit `localhost:5001` to ensure that still works and no syntax errors
- otherwise, not tested

Reviewers: spicyj, xymostech

Differential Revision: http://phabricator.benalpert.com/D222