Channel url and cursor fix

- Allow colons in channel urls
- Only add the channel part in the context menu
- Fix cursor not changing between separator and url
Fixed munging of whitespace in sysinfo's matching functions
Closes #712
Allow multiple channels in url, fix nick re

- Multiple channels have to be separated by a comma
- Fix #nick becoming a url for nick instead of #nick
Add ObsidianIRC network

#412
Merge pull request #718 from Farow/pull

Channel url improvements