Renamed in templates/units to apply a consistent naming scheme:
* all champion files
* all *_kardakes_* files
* all *_marine files
* all *_merc_* files
* Greek thorakites and thureophoros files
Furthermore:
* applied “equine transport” requirement to Persian trireme
* removed now obsolete pers_cavalry_*_trireme files
* Athenian docks can no longer train marine soldiers (to prevent other factions from training their own units at captured Athenian docks).
* the cart *_gaul, *_iber, *_ital files are kept unchanged for now.
* the *_black_cloak files are kept unchanged for now.
All unit templates appear twice (once for adding the file with its new name and once for deleting the file with its old name), so this patch is actually smaller than it appears at first glance.