SUMMARY:
This includes some small cleanups, and the addition of a new driver for the
Orange Micro iBot2 (not functional yet)

PER-FILE CHANGES:
Makefile:
- ov511.c no longer needs -DEXPORT_SYMTAB
- Keep track of decompressors separately from other objects
- Add ovfx2 driver

ov511.c:
- Optimize ov_w_mask() for mask == 0xff
- Switch regval arrays and related functions over to new "struct regval" type
- Get rid of some Hungarian notation and StudlyCaps
- Move two discrete OV518 register settings into the register arrays
- Minor cleanups

ov511.h:
- Rename struct ov511_regvals to struct regval, remove useless enum, add mask

ov7x20.c:
- Make contrast register table static; saves 16 bytes of stack

ovfx2.c:
- Driver added. Not functional yet.