Merge branch 'pw/p4-use-client-spec-branch-detection'

Merge branch 'pw/p4-use-client-spec-branch-detection'

Fix "git p4" when "--use-client-spec" and "--detect-branches" are
used together (the command used to misdetect branches).

* pw/p4-use-client-spec-branch-detection:
  git p4: make branch detection work with --use-client-spec
  git p4: do wildcard decoding in stripRepoPath
  git p4: set self.branchPrefixes in initialization
  git p4 test: add broken --use-client-spec --detect-branches tests
  git p4 test: move client_view() function to library