Line title handling dependent on used data series

[paulk]

An idea to make Postproc a bit less tedious to work with:

0) if a chart is created from single data series, use $quantity as line title
1) If a chart is created from same project, but different quantities, use $quantity as line title
2) If a chart is created from different projects, but same quantities, use $project as line title
3) if chart is created from same project and same quantities, use $basename as line title
4) etc...

(it might be just my workflow - or maybe i'm using it wrong - but currently it seems that most of my time is spent by pasting "$project" and "$basename" to the "line title" fields)