add third party software version numbers to About.html
fix: stoneDistanceFromFingertip calculation no longer depends on GoGame
stoneDistanceFromFingertip factory default value is now 100% on iPhone

with the new simplified stoneDistanceFromFingertip calculation algorithm in PlayView
(cf. commit eeb2693), the best factory default value is no longer 50%, but 100%.
don't attempt linear conversion when stoneDistanceFromFingertip user preference is upgraded

the semantics of the stoneDistanceFromFingertip user preference value changed when the new
simplified stoneDistanceFromFingertip calculation algorithm in PlayView was introduced (cf.
commit eeb2693). it therefore makes not much sense to attempt a linear conversion of the old
user preference value when user defaults are upgraded. instead we use a binary approach:

- if the old value indicates that the user wants *some* distance, we give the user the new
  optimal value of 100%
- if the old value indicates that the user does not want any distance, we leave the value at 0%
fix document interaction handling during app launch

the problem was a dependency bug introduced in commit bc9cea9: setupFolders depends
on self.documentInteractionURL being set, but document interaction handling occurred
too late. the fix is to perform document interaction handling earlier during app launch.
improve document interaction handling success/failure messages