use default search title from speeches app
link in green instance header to edit instance details
remove almost all of the user dropdown menu
Merge remote-tracking branch 'origin/244-homepage-tweaks'
Add missing things to requirements.txt.
Small text change i.e. to e.g.
Document roles of get_transcripts and parse_transcript.
Add a couple of methods to make it easier to set options in subclasses.
Make sure the data directory in scrapers is created.

Adding a file to this directory will make sure is there - using
.gitignore seems harmless.
Shift most of scrapers/utils.py to SayIt
Change existing scrapers to use helper classes from SayIt.

I've checked that these all function, except for the Charles Taylor
one - www.sc-sl.org is currently down.

For now, let's leave out the philadelphia scraper, which is going to disappear
from sayit.mysociety.org altogether.