After numerous tests it was found the splice features were at best
the same performance as standard IO and at worse actually slower.
To simplify the code all splice features are removed.
* Replace the stat values with a crc32b of them instead (for auto-cache)
* Replace char flag with bitfield
* Remove node generation. nodeid is an unsigned 64bit int. Would take 500K+ years
to rollover at 1M nodes per second.
* Remove request interrupt code. Required tracking of all requests unnecesssarily.
* Remove all debugging printing. Have plans to do full replacement.
* Remove deprecated functions.
* Remove unneeded error checking.
* Remove "userdata" which was unused.
* Remove allow_root feature.
