* when dir system/cache is not writable by the webserver, then show some
nice notice to the user about it instead of http 500 error
* remember client version and usage stats checkbox in session on install
* fixed some small warning introducted yesterday about
highscores_ids_hidden
* updated TODO
* fixed hidding shop system menu on tibiacom template when disabled in
config
* some changes to sample characters: chanced town_id to 1, posx: 1000,
posy: 1000, posz: 1000 and default group_id to 1 so you can change
in-game outfits and they will be used
* fixed account.login redirect not working on tibiacom template
* installation: warn about wrong admin account name/id and password
* (internal) removed some duplicated code on install finish
* (internal) renamed installation step files to be in correct order
* added TODO file
* bumped version to 0.7.3
