Add compiler identification + fix a typo.

Fixed a typo and added compiler identification.
isHotkey parameter for actions & spells
Merge pull request #1020 from EvulMastah/hotkeyparameter

isHotkey parameter for actions & spells (runes)
Merge pull request #1015 from dominique120/master

Add compiler identification + fix a typo.
Prepare our Lua API for future changes to capacity/weight

This commit may break backwards compatibility! It prepares the Lua API
for changes proposed in this comment:
https://github.com/otland/forgottenserver/pull/1010#discussion_r18741870
so that we don't have to break backwards compatibility in 1.1.
Change Player.setCapacity to be consistent with other functions
os.mtime more precision to timing

Since os.time doesn't return time in milseconds precision and for some
exhaustion scripts it's really necessary, I implemented this function.
Merge pull request #1022 from conde2/master

os.mtime more precision to timing
Configurable classic tibia slots and fixed modern-hand slots (Closes #401)
Renamed classicSlots variable
Merge pull request #1021 from EvulMastah/classicslots

Configurable classic tibia slots and fixed modern-hand slots
Merge pull request #1023 from EvulMastah/creatureicons

Skulls available for all creatures