Add support for named parameters to FShell

[TheFriendlyCoder]

It would be nice to be able to specify the parameters for an action method in an arbitrary order by naming each parameter and it's associated value, as in:

MyCommand param3=a param2=b param1=7

So if one had an action method that looked like this:

def do_MyCommand(self, param1, param2, param3):
    print(param1)
    print(param2)
    print(param3)

We'd see something like this:

7
b
a