Weapon Reassembler (WIP) 0.4beta

- Some small fixes, optimisations and fireballs ontop of that
- More feedback on simple error pre-checks (watch for that new shiny text)
- Semi-working elemental switch (see limitations). If you disable ALL the mod options except elemental change, template gun is NOT required.
- Not documented before, but now modified weapons use custom tooltip showing a label "Custom" on modified guns.

KNOWN LIMITATIONS:
* Can't change primary fire element for common weapons. Even if it *appears* to be changed, it's still physical. All common-quality vanilla weapons have no element attached. Don't know if I will be able to override that (do I really need to?)
Secondary fire element for common-quality weapons is changed ONLY when simultaneously copying secondary fire ability. Yes, now you can put an Energy Lance on your common assault rifle. Dunno why you would want to, but here it is.
* Uncommon and rare-quality guns can't be changed to "physical" damage.
More accurately: you can try but the engine resists my efforts to.
* When changing elements, gunfire sound stays the same (i.e. is you mod fire rifle into poison rifle it still sounds like fire when shooting).

KNOWN ISSUES:
* Preview uses the color scheme of a template gun, but the resulting gun uses the color scheme of the original.
It's the preview which is wrong. Bad preview! Will be fixed, but not a high priority.

WARNING!
I thought it to be self-evident as I post updates under "alpha" but since this is an "alpha of an alpha" I'd like to reiterate. I minimally tested this and use it myself, but this mod (and especially this update) can potentially break your weapons.
Please report any and all cases of broken weapons; the more info, the better.