Update compiler

Here a first batch. As it would be probably a bad idea to fully update compiler v3.0 to v3.2 ; we can at least push fix for some known annoying issues/crashes and adding minor welcomed features. This doesn't deal with opcodes or such at all.

Most of patches come from commits from SourceMod, some from SA-MP community and few others from some Pawn version (diff from previous version). I've put reference in each commit. So if one addition feels wrong, we can easily revert.

When I could, this has been tested before and after. This should be safe.