render resize windows retina-correctly
Make all workspaces starting with "__" internal

Workspaces won't work properly if they start with "__", so reserve that
namespace altogether. Disallow renaming workspaces to reserved namespace
and using reserved namespace in configuration.

Fixes #1209.
add a testcase for the previous commit (internal workspaces)
improve error messages for i3-internal workspace names
Dont include dock clients in ewmh lists

http://standards.freedesktop.org/wm-spec/latest/ar01s03.html#idm140251368149456

The _NET_CLIENT_LIST property of the root window:

> These arrays contain all X Windows managed by the Window Manager.

Dock clients are not managed windows, so they should not be included in
_NET_CLIENT_LIST or _NET_CLIENT_LIST_STACKING.
i3bar: reinit colors on barconfig update

Allows bar colors to be updated on barconfig update events, such as with
the ipc command `reload`.
Refactor binding accessor

Change the primary binding accessor to `get_binding_from_xcb_event`.

This function gets a binding from a generic xcb event of type KeyPress,
KeyRelease, ButtonPress, or ButtonRelease by determining the input type
(keyboard or mouse), the modifiers pressed from the filtered event
`state`, managing the proper fall back in case mode switch is enabled,
and finally querying the bindings for a binding that matches the event.

The logic of querying keyboard bindings is not intended to be altered by
this change.

The general accessor has been slightly modified to work with mouse
bindings and made private because it is only used in bindings.c
Test workspace empty event semantics

This patchs provides testcases for the workspace "empty" event.
Feature: improve active window request handling

Allow client requests of type _NET_ACTIVE_WINDOW to switch workspaces if
they indicate they are a pager. Otherwise, set the urgency hint on that
con to indicate that something happened.

This allows task switchers like skippy-xd to work properly.

http://standards.freedesktop.org/wm-spec/latest/ar01s03.html#idm140251368127856