Support for escaping comment symbols in configuration file.

[helgihg]

I wanted to color the incoming/outgoing messages using the config file instead of command arguments, like this:

save-history = true
debug = true
contacts-autohide = true
show-inline = true
one-sided = true
show-names = true
color = ["\#0aa", "\#bb0"]

But I ran into the problem that the # symbol which is used to specify colors precisely, conflicted with the same symbol being used to indicate a comment.

I thought of changing how colors were handled, i.e. by removing the # from color definitions, but that would be a software design decision that I felt uncomfortable making.

This allows hash symbols in configuration values by escaping them. It shouldn't break existing configurations.