#492 Logscale for paxis

[Sebastian Engel]

In a parallel plot, i would like to draw a parallel axis with log scaling (Obj2 in the attachted example).
Following the manual, set paxis n tics is using the syntax from xtics and alikes.
However, the respective options from xtics, logscale, seems not to be respected by paxis tics.

I haven't fully followed the sequence of the parallel plot generation yet. Though, i have seen some intersections with paxis in a spider plot. So a change on the parallel axis creation might have some more complications, i guess.
Moreover, i couln't find any checks of logscale prerequirements, such as values>0 as for normal axis. So i guess, this feature might have not be considered (or maybe was ruled out).