Play order sync pattern from playlist

I've added a new sync pattern that adds the PlayOrderIndex of the track from its playlist.

For example, if my playlist looks like this:
*Blue Skies - Artist1
*Home - Artist 2
*Without - Artist 3

...then the sync pattern would rename those to "001 - Blue Skies - Artist 1," "003 Without - Artist 3", and "002 Home - Artist 2". 

This is useful mainly for car steroes, where the order in which tracks are played depends on the file names (alphabetically/numerically) and cannot be changed on the fly. Adding the playing order from the iTunes playlist allows us to have some control over which song shows up first.

The pattern is %TRACKNUMINPLAYLIST%, and renames the files according to the _PlayOrderIndex_ - _Track_ - _Artist_. I've also added some leading zeroes to _PlayOrderIndex_ to preserve the order correctly. 

It seems to work, according to my requirements!