Merge branch 'maint'

* maint:
  GIT-VERSION-FILE: check ./version first.
  sha1_file.c: Round the mmap offset to half the window size.
  Make sure packedgitwindowsize is multiple of (pagesize * 2)
  Add RelNotes 1.5.0.1
  Still updating 1.5.0 release notes.
  git-daemon: Avoid leaking the listening sockets into child processes.
  Clarify two backward incompatible repository options.