Merge branch 'master' into next

Merge branch 'master' into next

* master:
  Makefile: install 'git' in execdir
  git-svn.txt: fix description of fetch flags accepted by clone.
  git-svn.txt: fix fetch flags incorrectly documented as init flags.
  git-svn.txt: make formatting more consistent.
  git-svn.txt: stop using dash-form of commands.
  Documentation: update description of shell aliases
  MinGW: truncate exit()'s argument to lowest 8 bits
  gitweb: add empty alt text to avatar img
  gitweb: picon avatar provider
  gitweb: gravatar url cache
  gitweb: (gr)avatar support
  gitweb: use git_print_authorship_rows in 'tag' view too
  gitweb: uniform author info for commit and commitdiff
  gitweb: refactor author name insertion
  http.c: add http.sslCertPasswordProtected option
  http.c: prompt for SSL client certificate password