Improve install handling of 'LNP/Tilesets/*'
Improve install handling of 'LNP/Tilesets/*'

A less generic file from a graphics pack will no longer be overridden if something in Tilesets has the same name.  Allow both files and directories as Tilesets content.  The former is helpful and the latter required for Mifki's forthcoming changes to the TWBT configuration style.  See http://www.bay12forums.com/smf/index.php?topic=138754.msg6078135#msg6078135

PeridexisErrant/python-lnp,PeridexisErrant/python-lnp