[#251] added info about exchange rates source
[#28] added cancel button to contact form
[#28] ask before cancelling contact edit
appcast code: better styles
appcast code: use versions, not build numbers
updated some strings files
added script for reusing translation strings

e.g.
./reuse_translation.rb Localizable.strings "Cancel" \
  HINewContactViewController.strings "WNT-Ju-zbY.title"