Merge pull request #8 from kyzentun/AMV_Kyzentun

Replaced ClearVertices and RemoveVertices with SetNumVertices.
simplified functions. updated warnings, get functions are for current state

It was warning about FirstToDraw = 0 >= vertices.size() = 0.
SetVertex must provide index

A default doesn't make sense anymore.
Added Documentation

lua docs and actordef.txt
fixed int vs size_t mismatches, add checks to lua args before sending to c
Replaced SetDrawMode, SetFirstToDraw, SetNumToDraw with SetDrawState.  Moved DrawMode to be inside the tween state.  Removed CheckValidity hack, SetDrawState checks that the new state is valid before setting it.  Changed GetSafeNumToDraw to take a parameter for num.  Replaced GetFirstToDraw with GetDestFirstToDraw and GetCurrFirstToDraw, same for GetNumToDraw and GetDrawMode.