ActionElement.h: Replace defines, remove superfluous ";"

Defines do not follow scope rules, but enums do. Enum classes
even utilize strong type checking (but i am not sure about compiler
support for c++11 on all target platforms).
Replace defines in Damage.h with enums.
Fix some cppcheck warnings (mostly style and postfix vs prefix iteration)
Fix typo ActionLayer::receiveEventPlus(...)

This method is rarely used, however it returned 0 after adding stuff.
It now returns the sum.
Remove variables flagged for removal (via conditional TODO comment)

x and y is provided by PlayGuiObject::Pos.
Get rid of two more define groups.
Fix FTBFS
Merge branch 'cleanup' into defines

Merge cleanup codings style commit as i accidentally used that branch as
the base.
Merge branch 'master' into defines
Use style guide
Merge pull request #557 from ZobyTwo/defines

Defines/Typos