Various fixes and balancing

--Cannon and short-barrel cannon models are now skinnier
--CoH sounds fixed
--Small v12 petrol/diesel and medium v8 diesel weight slightly increased
--Large CVT torque rating increased from 3400 to 6000
--37mm cannon name fixed
--37mm short-barrel cannon rof adjusted
Some new tank sounds

Engine and a few misc
Resampled new sounds to 44100 hz
Diesels more durable

Diesel engines have much more hp, and can take more damage before
performance degrades
Merge remote-tracking branch 'remotes/upstream/master'

Conflicts:
	lua/autorun/acf_globals.lua