Removing WPS conditional bitmap hardcoded limits.

[gl]

In my work-in-progress WPS I wanted to use 15 volume segment bitmaps instead 
of the hardcoded 10.

The solution (for enums that are based on an internal value) is to simply 
count the number of enum conditionals a particular WPS is using when 
formatting it, and work off that.  This allows a WPS designer to use however 
many conditional bitmaps he chooses, but without breaking backwards 
compatibility.

I've currently hard-coded it for the %?pv tag as a proof-of-concept.  Does 
anybody more familiar with the WPS code want to make it work for all 
value-based enum conditionals?
--
gl