Remove chat window opening animation
Update chat menu to properly position itself when opening

The previous implementation seemed to assume a full-screen main window -
it will now open on the right side of the window, vertically centered,
regardless of where the main window is.
Fix centering of timestamp in chat window
Fix odd resizing of chat messages

When calling updateGeometry on the message labels the layout system
seems to resize the widgets in weird ways.  There may be a different way
to keep it from doing this.
Update behavior of chat window close button

Use a stylesheet to suppress highlighting of the background when
pressing the button down.  Instead, it will change the image.

Unfortunately I wasn't able to find a way to do this without requiring
an extra image, or by doing it through the icon system.  The different
icon states didn't seem to take effect for button presses, and using
opacity in the stylesheet doesn't work yet for `QPushButton`s.
Update chat window to only scroll when at the bottom

It can be frustrating when scrolling up to read a message to have the
window forcibly scrolled to the bottom when a new message appears.
Fix chat message formatting and word wrapping

By switching from a QLabel to a QTextBrowser widget more formatting
options and word wrapping that breaks words is possible.  It comes with
an issue I have been unable to resolve

 * Selecting text and going down with the cursor will cause it to
   scroll.  It's possible to increase padding to remove this behavior,
   but it doesn't look great.
Add chat window dragging

This was originally implemented by Mohammed Nafees, shared on Basecamp.

I've noticed an issue with dragging across screens (monitors) where the
chat window will jump vertically.  I've tried debugging it, and
ultimately it looks like an issue with the `move` method.  The
coordinates are valid (I tried using global coordinates as well), and
the amount to move is correct, but when moving to coordinates on a
different screen it doesn't do the right thing.
Cleanup ChatMessageArea.cpp
Remove extraneous debug messages
Merge remote-tracking branch 'upstream/master' into 19554

Conflicts:
	interface/resources/resources.qrc
	interface/ui/chatWindow.ui
Update resource urls for chat window close button
Update chat window to not allow movement while docked
Move ChatWindow isAtBottom and moveToBottom outside of HAVE_QXMPP
Merge pull request #2660 from huffman/19554

19554 Continue refining Chat