Hopefully #10 fixed (ha-ha-ha)
src xpath handling improved
I'm on my way to fix #14
GoToPercent uses number of pages if available.

GoToPercent now checks the cache status. If everything is preloaded - it
uses total number of page to calculate the target page.
Merge pull request #16 from M0ns1gn0r/SetPercentFix

GoToPercent uses number of pages if available + some comments
Merge pull request #2 from Litres/master

update from base