added new functionality to nxos_command
added new functionality to nxos_command

* commands argument now accepts a dict arguments[1]
* waitfor has been renamed to wait_for with an alias to waitfor
* only show commands are allowd when check mode is specified
* config mode is no longer allowed in the command stack
* add argument match with valid values any, all

[1] The commands argument will now accept a dict argument that can
specifiy the output format of the command.  To specify a dict argument
use the form of { command: <str>, output: <str>, prompt: <str>,
response: <str> }.  Command and output are required arguments. Output
accepts valid values text and json.

thaim/ansible,thaim/ansible