added todays statistics in a new Fragment type with a WebView,
Small due chart changed to new chart engine,
moved ChartView in main package
updated statistic Fragment layout context
prepareDrawables is now only called once as long no additional drawables are added
put options menu relevant methods to abstract base Fragment.
fixed "web page not available" on older devices for today statistics
Merge pull request #435 from trashcutter/stats_today

Added Today statistics, removed achartengine dependence from smal due chart