Using IF_VARSIZE and IF_FIT flags to generate fitted clothing 

Cutting down on the need to have separate item types for fitted clothes.

The IF_VARSIZE flag is used to identify clothing item types that can come in different sizes.

When clothing with the IF_VARSIZE flag is generated in map::add_item code, there is a one in 3 chance that it will fit the character and be given the IF_FIT flag.

The IF_FIT flag is used in the player::encumb function to reduce fitted clothing encumbrance by -1.  Similarly used in the item description code when displaying encumbrance.