* Added parameter description for match_all in cmd_add_rule
    * Docstring for decorator in Match()

    * Renamed configuration variable dgroups_app_rules:

        Reason:

                I could not understand its purpose after reading the
                Qtile documentation as i first i had a look at Qtile
                before i was actually trying it and configuring it.

                Because it wrote about dgroups and key mappings, so that
                i thought that this feature is only for automatic
                generation of groups. And the Rule only for such groups.

                But this is wrong. It can actually be used to specify
                some special stuff when you have "Group" with
                exclusive=True.

                By defining a Rule without a group you can make some
                specific applications intrusive. Example:

                Rule(Match(wm_class=['Pinentry']), group=None, intrusive=True),

                By just leaving out group you specify rules for apps/windows.

                Which is nice if you got some programs which are actually working
                together and are own applications which would be put into a new
                dynamic group because of exclusive=True.

                So i would call it app_rules. dgroups_key_binder as a variable name
                is ok. Because it maps actual dynamic groups.

                So it is necessary to just say if you define a Rule with a nonexistent
                Group then it is a dynamic one. But if one is existent, then it just
                maps some settings to specific matched applications/windows.