Summary of changes:
  - Remove palette conversion and related code
  - Full OV518 support (except for color), initial OV518+ support
  - Improved OV6620 quality (Credit: Alexandre F.)
  - ov51x_init_isoc() should exit if usb_submit_urb() fails
  - ISO completion handler should only issue warning if bad data is received
  - Added "mirror" module parameter; reverses image horizontally
  - Changed USB control transaction fields to match Windows driver
  - New decompression module locking (decomp_ops->owner), per Greg's advice
  - EXPORT_SYMBOL_NOVERS => EXPORT_SYMBOL
  - New devices: Lifeview USB Live TV PAL/SECAM and PAL D/K+B/G
  - Disabled buf_timeout feature. It was calling vfree() in interrupt
    context, which is illegal. Memory is deallocated immediately on close().
  - Most sensors thought to be OV7620AE were actually OV76BE. Changed code
    to reflect this, and emit a warning if an OV7620AE is encountered.
  - Miscellaneous cleanups and bug fixes