0027074: Support of multi-span cache in Geom[2d]Adaptor

0027074: Support of multi-span cache in Geom[2d]Adaptor

The multi-span cache is stored as matrix (for surface) or vector (for curves) of caches. Each cell corresponds to a span. The cache is initialized on first call and destroyed when adaptor is destroyed.

1. Multi-span cache for curve and surfaces.
2. Revision of BSplSLib_Cache and small improvements.
3. Renew cache when loading same curve/surface into adaptor.
4. Optimizations for single-span cache
5. Remove unused constructors in BSpl*Lib_Cache classes
6. Allocate cache on first call, not when loading a curve/surface
7. Note in upgrade.md about multi-span implementation