Trying to read from the sql database from another process was flaky.
This adds a debug-dump-history command which is used by the history BDD
tests to validate the history contents.
It outputs history in the old pre-SQL text format, so it might be
useful for those who want to manipulate their history as text.
Now that sql is only used for history (not quickmarks/bookmarks) a number of
functions are no longer needed. In addition, primary key support was removed as
we actually need to support multiple entries for the same url with different
access times. The completion model will have to handle this by selecting
something like (url, title, max(atime)).
This also fixes up a number of tests that were broken with the last few
sql-related commits.
When a redirect occurs, the item is saved in history with a -r suffix
now. When opening qutebrowser that's picked up and the item is hidden
from completion.
