db/schema/openquake.sql, engine:

Removed mentions of input reuse on some comments.

This functionality was recently removed.
calcs/hazard/general:

Removed some (obsolete) input reuse logic from `initialize_sources`.
Merge pull request #1148 from larsbutler/cleanup-input-reuse

Cleanup input reuse

[r=matley] [f=*trivial]
Merge branch 'master' of https://github.com/gem/oq-engine into taxonomies-imt