When handling user input sent over the protocol, split apart messages
on QChar::LineFeed, processing and displaying each as individual
messages sent one after the other. This applies to /query, /say,
/notice, and /me. Otherwise, the IRC protocol interprets anything
after each line break as a new message.
Fixes inability to send multi-line content via copy-paste on
Quasseldroid. Quassel desktop currently works around this issue by
sending multiple individual messages for every line break.
Test case:
1. Install Quasseldroid (stable or alpha), connect to a core
2. Copy some text to the Android clipboard that has a line break in
it (not just word-wrap).
3. Paste into Quasseldroid
4. Send message
Before: Message shows up with line break (LF character on desktop),
IRC server treats all lines after first as raw commands.
After: Message gets split into multiple smaller messages at each
line break.
This should also work for /query, /say, /notice, and /me.
See: https://tools.ietf.org/html/rfc1459#page-8
Closes GH-263.