Issues/897 custom hansard view

the /hansard/<id> view wraps /speeches/section/<id> but:

 - has a more relevant url
 - in future will also check that the data is coming from the hansard section (or perhaps better, use the 'hansard' sayit instance?)
 - the templates from sayit speeches app have been copied over and modified to allow the urls to point to the /hansard ones and back to /person/slug, instead of the /speeches/speaker etc. ones

requesting review of this especially as I don't know if some of the things (subclassing SectionView to SASectionView, using a templatetag to do the speaker_id -> person url resolution) are reasonable django practice!