Bang searches without an actual query (i.e. just searching "!gh") will
now redirect to the home page. I guess people do this for some reason
and don't like that it redirects to the correct bang result URL, but
without an actual search term.
Fixes#595
Initializing the DDG bangs when running whoogle for the first time
creates an indeterminate amount of delay before the app becomes usable,
which makes usability tests (particularly w/ Docker) unreliable. This
moves the bang json init to a background thread and writes a temporary
empty dict to the bangs json file until the full bangs json can be used.
Using `format` for formatting bang queries caused a KeyError for some
searches, such as !hd (HUDOC). In that example, the URL returned in the
bangs json was `http://...#{%22fulltext%22:[%22{}%22]...`, where
standard formatting would not work due to the misidentification of
"fulltext" as a formatting key.
The logic has been updated to just replace the first occurence of "{}"
in the URL returned by the bangs dict.
Fixes#513
DDG style bang searches can now have the bang (!) at the end of
the search (i.e. "bologna w!" will now redirect to wikipedia just like
"bologna !w" would)
The app/utils/*_utils weren't named very well, and all have been updated
to have more accurate names.
Function and class documention for the utils have been updated as well,
as part of the effort to improve overall documentation for the project.