Merge remote branch 'ko/master' into jc/read-tree-cache-tree-fix

Merge remote branch 'ko/master' into jc/read-tree-cache-tree-fix

* ko/master: (2325 commits)
  Git 1.7.2-rc2
  backmerge a few more fixes to 1.7.1.X series
  fix git branch -m in presence of cross devices
  t/t0006: specify timezone as EST5 not EST to comply with POSIX
  add missing && to submodule-merge testcase
  t/README: document more test helpers
  test-date: fix sscanf type conversion
  xdiff: optimise for no whitespace difference when ignoring whitespace.
  gitweb: Move evaluate_gitweb_config out of run_request
  parse_date: fix signedness in timezone calculation
  t0006: test timezone parsing
  rerere.txt: Document forget subcommand
  t/README: proposed rewording...
  t/README: Document the do's and don'ts of tests
  t/README: Add a section about skipping tests
  t/README: Document test_expect_code
  t/README: Document test_external*
  t/README: Document the prereq functions, and 3-arg test_*
  t/README: Typo: paralell -> parallel
  t/README: The trash is in 't/trash directory.$name'
  ...

Conflicts:
	builtin-read-tree.c