If we set an instruction as ready twice, it decreases the transaction's
num_waiting a second time and applies the transaction earlier than it
should. This no doubt has undesired effects, probably resulting in a use
after free.
Hopefully fixes the first part of #2207.
A flash of background was happening for two reasons:
1) We were using the xsurface's dimensions to check if the surface is
ready, but these are pending dimensions.
2) In my particular setup, the default geometry of the xsurface does not
intersect any output, which prevented it from receiving a frame done
event. This made the transaction time out and the client would only
redraw once it's been rendered.
* The arrange_foo functions are now replaced with arrange_and_commit, or
with manually created transactions and arrange_windows x2.
* The arrange functions are now only called from the highest level
functions rather than from both high level and low level functions.
* Due to the previous point, view_set_fullscreen_raw and
view_set_fullscreen are both merged into one function again.
* Floating and fullscreen are now working with transactions.
