Encoding option for ipfs object get/put

[jgraef]

Both ipfs object get and ipfs object put have an option to specify the encoding. ipfs get has --encoding and ipfs put has --inputenc.

I propose to use --encoding for both to make it more uniform.

[whyrusleeping]

--inputenc specifies the encoding of the data that the command takes as input. --encoding specifies the format of the output of the command. They won't necessarily always be the same

[jbenet]

maybe --enc-in and --enc-out (or --codec-in and --codec-out ?)

if we were to change, we can keep the current names as aliases for the new
ones (forever, or maybe with a deprecation warning)