relative x and y in pan gesture are relative to first touch events
smoother relative panning in scrolled pages
fix debug on/off toggle
remove global variable DEBUG
less verbose on fallback text rendering
Merge pull request #346 from chrox/master

smoother relative panning in scrolled pages
various fixes and features in koreader-base
Merge pull request #347 from chrox/master

various fixes and features in koreader-base
Revert "various fixes and features in koreader-base"

This reverts commit ef23357d073eb304843b7648a31118c5ace39c97.
udpate koreader-base