hammer(8) - Remove 'status' directive.

  It wasn't working, it was undocumented and directive 'pfs-status'
  supersedes it.
libhammer - Few fixes to libhammer_get_volinfo()

* Fix a couple memory leaks.
* Reword some comments.
* While here fix info.c file width to 80 columns.
hammer(8) - Allow specifying paths to 'info' directive.
libhammer - Use source directory header instead of the system one.

* Instead of using libhammer.h from /usr/include, use the one that's
  in the source directory to build the library itself.