Cursor patches

[H. Verbeet]

Regenerated against git HEAD for whoever cares about these things.

Changes since last time:
  - user: format warning fixes
  - user: initialise cursor16 to 0 in destroy_cursor()
  - user: fix a small compile problem in the 6th patch, caused by
splitting things up. (The 8th patch removes the relevant block)
  - server: remove redundant NULL checks before free()
  - server: fix a memory leak in destroy_cursor()