sitescripts: Unmerged changes

Since we aren't going to merge the branch for 8492019, there are a couple of changes and fixes missing. I've put them all in this review.

The most notable change is that we're importing sites directly into the database instead of generating import statements, like we had discussed earlier.

[Wladimir Palant, 2012-12-21 14:30:30]

LGTM with the two comments addressed

http://codereview.adblockplus.org/9045097/diff/1/sitescripts/crawler/bin/impo...
File sitescripts/crawler/bin/import_sites.py (right):

http://codereview.adblockplus.org/9045097/diff/1/sitescripts/crawler/bin/impo...
sitescripts/crawler/bin/import_sites.py:57: cursor.execute("INSERT INTO
crawler_sites (url) VALUES (%s)", url)
Add _get_db().commit()? Otherwise this might bite us if we ever decide to call
that function multiple times.

http://codereview.adblockplus.org/9045097/diff/1/sitescripts/crawler/bin/impo...
sitescripts/crawler/bin/import_sites.py:57: cursor.execute("INSERT INTO
crawler_sites (url) VALUES (%s)", url)
Use INSERT IGNORE in case the URL is already in the database or duplicated in
the history?