Add a @finalize decorator for functions to be run on the result of all subroutines.

[bckohan]

For symmetry with @initialize

Check - not redundant with result_callback on an initialize?

[bckohan]

You can currently do something like this, but its very awkward:

class Command(TyperCommand):

    def finalize(self, **kwargs):
        pass

    @initialize(result_callback=finalize)
    def init(self):
        pass

    @command()
    def cmd(self):
        return self

Or this for chainable commands:

class Command(TyperCommand, chain=True):

    @staticmethod
    def finalize(result, **kwargs):
        self = result[0]

    @initialize(result_callback=finalize)
    def init(self):
        pass

    @command()
    def cmd(self):
        return self

Would prefer to be able to do something like:

class Command(TyperCommand, chain=True|False):

    @finalize()
    def finalize(self, results):
        pass

    @initialize()
    def init(self):
        pass

    @command():
    def cmd(self):
        return self