vehumet implemented with a duration and a slightly better spell choosing algorithm. still no saving, and a lot of other // TODO: 's
Whitespace fixes
Vehumet wording/description tweaks
Merge branch 'master' into vehumet

Conflicts:
	crawl-ref/source/dat/descript/ability.txt
	crawl-ref/source/dat/descript/gods.txt
	crawl-ref/source/religion.cc
Save Vehumet gifting data.
Indentation fix.
Use a list instead of an array to store Vehumet's recent gifts.

Also, use it as a queue and drop older entries when max size is reach (10)
instead of aging the queue manually.
Shorten a variable's name.
Make Vehumet accept demon and holy kills, don't accept ally kills
Adjust some spell gifting messages
Some simplification.
Memorising a Vehumet spell takes a turn.
Add a missing MSG_OK
Merge branch 'master' into vehumet
Properly set Vehumet spell gift timeouts based on the memorised spell
Increase the duration of Vehumet spell offers, add a more prompt
Merge branch 'master' into vehumet
Minor Vehumet description tweaks

The "assists you in casting..." message already displays in the list of
powers.
Fix compatibility
Make Vehumet stop gifting when abandoned