AUTHORS.md: update list of contributors
magit-get-submodules: new function
magit-insert-{unpulled,unpushed}-module-commits: new functions
magit-insert-{unpulled,unpushed}-module-commits: use independent types
magit-get-submodules: return just the path
magit-submodule-fetch: new command
magit-submodule-fetch: don't stop if one module fails
Makefile: `all' is the default target now

This ensures that `magit-version.el' is generated.
Makefile: `lisp' now depends on `magit-version.el'
Remove info manual portions from Makefile
magit-post-command-adjust-point: only use get-pos-property if fboundp