Align Channel text/joins/parts on left with configurable margin

[jaxson5]

This a feature request

An extra adjustable column/tab to separate nicknames from channel/query text. It needs to be adjustable to be able to leave enough space for long nicknames, and to be able to maximise channel area otherwise.

This aligns all the text properly and makes high traffic channels much easier to read.

[IceN9ne]

This would likely require a complete rewrite of IrcView, which I would love to see happen someday as well.

Duplicate of #718 opened back in 2010 (pre-github).