Rename a query buffer to contain a newline can lead to a crashing quasselclient
Renaming a query buffer to contain a newline in the name can lead to a crash.
How to reproduce:
1. Rename a query buffer into a name that contains a newline (for example, using copy-paste of a multiline string)
2. Hover over buffername.
What should happen:
Tooltip is displayed normally
What does happen:
Version: v0.12.2 (git-9c5e6c6) || Protocol version: 10 || Built: May 20 2015 14:17:35
Don't allow newlines in buffer names
Since it is possible to enter newlines when renaming a buffer via
the GUI, we need to have a sanity check that cuts off the additional