MFC 203377-231538. This records mergeinfo for already merged

MFC 203377-231538.  This records mergeinfo for already merged
changesets, but brings in the following changes:

MFC 222326
    - Fix tftp_log() usage

MFC 223137
    - Man page updates

MFC 223487
    - Bring back syncnet() implementation from older tftp implementation.

MFC 229780
    - Spelling fixes for libexec/

MFC 229904
    - Fix warning when compiling with gcc46:
          error: variable 'bp' set but not used

git-svn-id: svn://svn.freebsd.org/base/stable/8@231539 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f