shFlags is a library written to greatly simplify the handling of
command-line flags in Bourne based Unix shell scripts (bash, dash, ksh,
sh, zsh) on many Unix OSes (Linux, Solaris, Mac OS X, etc.).

Most shell scripts use getopt for flags processing, but the different
versions of getopt on various OSes make writing portable shell scripts
difficult.  shFlags instead provides an API that doesn't change across
shell and OS versions so the script writer can be confident that the
script will work.

(Taken from http://code.google.com/p/shflags/)

Further divide the parse_args function up, to support automatic prefix expansion for all subcommands, except for 'feature start'

Implement the basic logic to resolve name prefixes passed to 'flow feature' into their full feature branch names, if unambiguous.

Created a second function called gitflow_test_clean_working_tree() that returns error codes instead of dies.

Rewrote gitflow_require_clean_working_tree() in terms of that.

Add a function that tests whether a specific commit is already merged into the given target branch.

Only difference is that the default equals to:
0	for git-flow-feature
1	for git-flow-{release,hotfix,support}

Only have network connectivity when explicitly asked for feature branches. This action is so common that it should be quick (very git-ish).

For hotfix and release branches, forgetting to update would be an unsafe thing to do, so we leave the fetch in there by default.

Conflicts:
	git-flow-feature
	git-flow-hotfix
	git-flow-release
	git-flow-support

Give all subcommands an optional setup() function that will be called by git-flow in order to let the subcommand initialize its environment.

Give all the branch-type subcommands a default explicit "list" action, too.

Order the functions inside each of the subcommands in a specific order, for consistency:
- usage()
- setup()
- cmd_default()
- cmd_list()
- cmd_help()
- parse_args()
- other commands

Refactored the subcommand invocation logic to form a more hierarchical structure and a cleaner design.

Don't prefix tag names with 'v'. If you want that behaviour, include the 'v' on the command line manually.