High: docker: replace 'container' argument with 'name'

I realized that the 'container' argument means something special in
pacemaker. In order to avoid confusion, the 'container' argument for
this agent has been changed to 'name'. Anyone using 'container' as
an argument right now will not be affected. The option still works, it
is depreciated now though.
High: docker: monitor_cmd option for executing status script within container