Removed callbacks class and replaced it with (cleaner) C callbacks.
Moved options enum to its' rightfull place in model header
Reordered and commented things in model header.
Removed width from API and width constant from common header since this feature
is NOT yet implemented and is not high priority so it's just literring the
API with confusing, unusable function for now (when called console would still be
80x24 but the messages will be max len as set via this api so there would be
78-width empty chars at end of each line)
Added color setting for propmpt line, by default it's white, as it was before.
Removed useless 'common' header file.
Moved the last two constants from it to model header.
Files that used it either include header of model too or needed only the
lua_State forward def (which they must do themselves now, but it is one line,
just like #include was and more meaningful compared to
including "LuaConsoleCommon.hpp" file so it's OK).
Added more safety to LuaConsoleModel::getFromRegistry,
we now use a 'bla_LuaConsole' metatable in registry for our lua type.
Added settable colors for frame and title.
Title is by default white (it's empty so it's not immediatelly visible if it's
not set).
Frame is by default 'DarkGrey' (a9a9a9ff from html colornames), which is change
from the current default  which was white (ffffffff).