Always draw equipment stats (even when 'empty' item is chosen)

This makes the behaviour same as in RM2k's RPG_RT.
Remove if (dirty) in Window_EquipStatus::SetNewParameters

After the last change it is no longer needed.
Merge pull request #339 from rohkea/master

Always draw equipment stats (even when 'empty' item is chosen)
Emscripten: Don't check for boost headers as the check is broken from fastcomp
Emscripten: Set the main loop and disable unimplemented SDL functions