This patch refactors the commands that use the mitchellh/cli library to
populate the command line flag set in both the Run() and the Help()
method. Earlier versions of the mitchellh/cli library relied on the
Run() method to populuate the flagset for generating the usage screen.
This has changed in later versions and was previously solved with a
small monkey patch to the library to restore the old behavior.
However, this makes upgrading the library difficult since the patch has
to be restored every time.
This patch addresses this by moving the command line flags into an
initFlags() method where appropriate and also moving all variables for
the flags from the Run() method into the command itself.
Fixes#3536
Passing in an empty quoted argument from the shell currently panics as
we never check the length being greater than 0 prior to indexing into
the first rune, as illustrated in the test in this commit.
We also fix the panic, treating an empty string for data as equivalent
to not having passed it in the first place.
This commit adds a -base64 option to the consul kv put command, which
base 64 decodeds the data prior to writing it. This can be used in
conjunction with `consul kv get -base64 key`.