Lua support for inheriting scale and rotation

Found out these were not parsed during exploring another problem with scaling (attachments not being axis-aligned with bones causes problems..) and fixing this one was rather simple. 

Only caveat is that when reading the values in, the typical Lua pattern of 'readvalue or defaultvalue' doesn't work as in practice we only read 'false' or it's nil - both of which are eventually evaluated to false, at least in Corona JSON parser - I'd imagine all JSON parsers should parse the string 'false' to the boolean false.