NEW FEATURES:
- OV518+ detection and support (like the OV518 though, no decompressor yet)
- Added functions for getting and setting exposure. Not way for user to set it
  yet, but it can be read from the info /proc file. 
- Auto-exposure can be disabled with the auto_exp=0 param. Not very useful yet.

BUG FIXES:
- "Raw data buffer overrun" should have been debug statement, not error message
- Makefile: don't use includes from /usr/include/
- i2c_algo_usb.c: modversioning and compile fixes

INTERNAL CHANGES:
- Cleaned up function names, to be less hardware-specific
- Optimizatios to ov511_reg_write_mask()
- Added I2C I/O functions for reading and writing a specific slave device (eg. 
  a TV tuner). Also added ioctls for user-space access to these functions.
- ov511.c/ov511.h: #defines for VIDs and PIDs
- ov511.h: Add struct and defines for I2C ioctls; incremented interface version
- ov511.h: Added primary_i2c_slave and exposure fields to struct usb_ov511
- Makefile: Target i2c works w/o editing makefile