Revert an ill-advised revert of a bug fix.

This reverts commit bf82319c1e3f828a055cedf93d7f9c48594aaf66.
Add a stack_size field to ammo and comestibles, defaulting to the starting number of charges.
Update JSON info documentation.
Make ammo stack_size consistent for each caliber, and meds' stack_size so that pills take up far less volume.
Pull in latest translations from Launchpad.
Merge more configurable stack sizing and latest translations.
Update changelog, motd, and versioning for release 0.8.