broadway: Remove window translation code

This is no longer used as we neutered gdk_window_scroll & co.
broadway: Simplify frame handling and make it ARGB32

This completely removes the delta compression and makes all buffers ARGB.
This is obviously slower, but this will be re-integrated later.
broadway: Add gdkbroadwaydisplay.h include
broadway: Implement gdk_window_begin_move_drag()
broadway: Always use client side decorations
Switch from sending png frames to our own encoding

This is based on the rolling hashes code from
http://cgit.freedesktop.org/~krh/weston/log/?h=remote

It works by incrementally calculating hashes for every 32x32 block
in each frame sent, and then refering back to such blocks when
encoding the next frame. This means we detect when a block matches
an existing block in the previous frame in a different position.
This is great for detecting scrolling, which we need now that
the gdk level scrolling is neutered.
broadway: Use zlib compression for broadway buffers

This imports the MIT licensed js unzip from:
https://github.com/imaya/zlib.js

and uses it to decompress in js on the client side.
broadway: Add rawinflate.min.js to EXTRA_DIST

In addition to 149b3af105bd493cf267a1b69a3661cdfa88a46c
demo: Make sure to add gtk3-demo.desktop to tarball

In addition to fc71414ada5b270a4c6c9775225f5cdc5d303f63