lua api: SetWeapon(ammoType)

fix broken speech bubble display in chat. caused by r1a6b9a98147c one line was forgotten when moving some code

more of the same

fix TryPlaceOnLand's ambiguity/messup wrt to making terrain indestructible (had boolean parameter for indestructible AND landflags parameters that could contain lfIndestructibly)

further WIP (better error messages)

placeSprite accepts any amount of landflags now; further WIP wrt cleanup/fixing

expose lfIndestructable, lfIce and lfBounce

Fix pas2c build

make enums crash-safe. and other fixes

WIP: PlaceSprite for lua API. also changed PlaceGirder so that it will return true/false for whether placing was successful too

fix possible engine crash that a lua script could cause by passing an invalid geartype to addgear

tiny lua documentation fix

uWorld does not require uMatrix anymore

fix hint and gl2 build. NOTE: this does not change that GL2 segfaults right away. that is an issue that dates back at least 50 commits, but most likely even back to the webgl merge. I guess nobody actually tried to run hedgewars in GL2 since back then :P