= Operator should check for self-assignment
Minor performance enhancement

`list.empty()` runs in constant time; `list.size` can run in linear time.
`list.empty()` runs in constant time; `list.size` can run in linear time.

Sources:
http://www.cplusplus.com/reference/list/list/size/
http://www.cplusplus.com/reference/list/list/empty/
Remove memory leak in RageSurfaceUtils::Palettize
Merge branch 'patch-2' of https://github.com/moshekaplan/stepmania
Merge branch 'patch-3' of https://github.com/moshekaplan/stepmania
Added semicolon that moshekaplan forgot.