Merge pull request #202 from oxyplot/develop

Merge develop
#208: remove wrong example
Update Xamarin.Forms assembly infos and nuspec
Add example from discussion 516060
#209: Add text rendering capability tests in the example library
Restructure folders in the example library
Delete obsolete ExamplesBase class
Split annotation examples into separate files
Add TagsAttribute to example library
Remove StyleCop SuppressMessage attributes in the example library
Minor documentation updates
Rename ArrayHelper to ArrayBuilder.
Move AxisUtilities.CreateTickValues to Axis.
Move ArrayHelper.GetHashCode to HashCodeBuilder
Mark unused methods obsolete
Move StringHelper.CreateValidFileName to test project, update tests
Rename ReflectionHelper.FillList to ReflectionExtensions.AddRange and change to extension method.
#210: Support binding to paths, e.g. "Point.X"
Add DrawCircle, FillCircle and FillRectangle extension methods
Implement IFormattable on OxyRect and OxySize
WindowsForms: change stringformat to GenericTypographic (tighter bounding boxes - as in WPF)
Add more tests on rendering capabilities
iOS: cache fonts, dispose paths