Generic parsers as flag types
removed extranneous value method on the generic type
Use HelpPrinter in ShowCommandHelp
Can now change these default flags in other applications
Merge pull request #86 from zenoss/upstream/feature/help-version-flags

Can now change these default flags in other applications
Merge pull request #84 from JackC/help-printer

Use HelpPrinter in ShowCommandHelp
Merge pull request #81 from zenoss/upstream/feature/generic-flags

Generic parsers as flag types
Add FlagNames() method to Context

It's often useful to list all defined flags prior to launching the
program for debugging/logging purposes. This takes away the boilerplate.
Adding VersionPrinter and tests.
making all pathing for cli local in tests for easier fork testing
running go fmt
add completion file for zsh
Fix global flags in Subcommands

closes #69
Merge pull request #106 from gemnasium/fix-subcmd-global-flags

Fix global flags in Subcommands
Starting to hack in some env var configuration goodness
Updating structs to use labels, adding tests for env stuff
Updating tests to pass `go vet`

Mostly lack of struct field names in literals and one sprintf format
specifier mismatch.
Adding struct field names to examples in README

Idiomatic Go
Addressing `go vet` offenses
Merge pull request #109 from modcloth/go-vetting

Go vetting