Merge branch 'maint'

Merge branch 'maint'

* maint:
  http: treat config options sslCAPath and sslCAInfo as paths
  Documentation/diff: give --word-diff-regex=. example
  filter-branch: deal with object name vs. pathname ambiguity in tree-filter
  check-ignore: correct documentation about output
  git-p4: clean up after p4 submit failure
  git-p4: work with a detached head
  git-p4: add option to system() to return subshell status
  git-p4: add failing test for submit from detached head
  remote-http(s): support SOCKS proxies
  t5813: avoid creating urls that break on cygwin
  Escape Git's exec path in contrib/rerere-train.sh script
  allow hooks to ignore their standard input stream
  rebase-i-exec: Allow space in SHELL_PATH
  Documentation: make environment variable formatting more consistent