More ID enhancements

• The size of each I.D. level will gradually increase with depth, and random layout parameters, including number of enemies etc., are adjusted in order to balance difficulty across different layouts.

• The I.D. will use a different layout/grid set for each level after the first:

Two exits will be generated per level (extra one separated from the start and the normal exit), each leading to a different layout/grid scheme, which will be reflected in the tile used for the exit. These are randomly determined using a normal probability distribution that tends to rotate through all possibilities as depth increases.

More layouts can have random rooms, and additional door grids have been added to the I.D. variable grids lists.

Stair guards (for both exits) are now generated randomly, making their presence more unpredictable (and slightly more common). The probability is a periodic function of depth (levels 5+, automatic at level 30+).

These changes let players choose/avoid certain level themes according their preferences and provide some insurance against any discrepancies in difficulty between layouts.

• The I.D. challenge quests have been adjusted:

The I.D. challenge award probabilities for a prodigy (more than 1 is very rare) or a category point (tends towards 1 per 30 character levels) have been adjusted based on how many have already been awarded and the number of character levels the player has gained in the I.D.

Quest text has been expanded and clarified in a few places.

• Some grid definitions have been updated to work better with the Nice Tiler.

• Fixed a bug with the "treasure1" vault that could allow its entrances to be blocked.