Add check for gear kind of hedgehog on invulnerability effect. This probably fixes bug #766, is similar to change in previous r2a1483d91977 and was introduced by r7d925e82e572

well. let's fix this at least - only apply to gears that are actually hedgehogs, not just ones associated with a hedgehog (which can be pretty much any gear since damage tracking was added)

Convert some ansistrings to pchars

drop redundancies for lua and physfs

fix linking physfs after a run of cmake

happy 10000th commit also fix the travis build by adding a system physfs library

fix build on travis

use bundled physfs on win and osx