Fixes#2303, as well as a crash.
To replicate the crash:
* Have multiple outputs
* In config: for_window [<criteria>] workspace foo
* Also in config: workspace foo output <left-output-name>
* Focus the right output, and ensure workspace foo doesn't exist
* Launch the app that triggers the criteria
When the view maps, it calls workspace_switch which calls
send_set_focus which calls cursor_send_pointer_motion which calls
transaction_commit_dirty. This call to transaction_commit_dirty is not
meant to happen at this time because the tree isn't guaranteed to be in
a consistent state, but I'm not sure how exactly this leads to the crash
or render issues.
In this case the transaction is already committed by the view
implementation's handle_map function. So the solution is to remove it
from cursor_send_pointer_motion and add it to the other functions in
cursor.c which call cursor_send_pointer_motion.