Merge branch 'maint'

* maint:
Document additional 1.5.3.5 fixes in release notes
Avoid 'expr index' on Mac OS X as it isn't supported
filter-branch: update current branch when rewritten
fix filter-branch documentation
helpful error message when send-pack finds no refs in common.
Fix setup_git_directory_gently() with relative GIT_DIR & GIT_WORK_TREE
Correct typos in release notes for 1.5.3.5

diff --cc git-instaweb.sh
Simple merge

diff --cc send-pack.c
Simple merge