structure descriptions and pretty print settings more

[tooomm]

It's really difficult to parse and find the needed options within all this %'s.

If you can't use some kind of tool tip for example, it would be helpful to have like a table: %s --> Subject %n --> Sender Name %u --> Account

I know that would make the settings page longer, but more useful.

[mkiol]

I fully agree with you... I'm slowly becoming convinced to #135 ;-)

[mkiol]

I did some improvements in the latest dev xpi.

[tooomm]

It looks way clearer 👍