Document several recent changes to vm_map_find(9):
- Document the max_addr parameter that restricts mappings to a subset of
  the map's address space.
- Document VMFS_ALIGNED_SPACE and update for the rename of VMFS_SUPER_SPACE.
  In addition, use a table that describes the different find space
  strategies in more detail.

Reviewed by:	alc
Approved by:	re (kib)
Fix a typo.

Approved by:	re (gjb)