add russian translation for time spans
add russian translation for now
add PR to release notes
add russian translation for future dates
Merge pull request #143 from mexx/ru-timespan

add russian translation for time spans
Danish translation
Add pull request to release notes
Fixed language code, spelling errors

Was using the wrong language code and fixed some spelling errors.
Changes text in TimeSpanWithPrecesion test.
Removed unneeded test + redundant spaces
minor cleanup
Merge branch 'danish2'
Introduce new localisable abstraction - INumberToWordsConverter

Move English, Arabic and Farsi converters to a separate strategies.
EnglishNumberToWordsConverter - promote units and tens maps to a static fields to reduce allocations.
ArabicNumberToWordsConverter - promote arrays to fields to reduce allocations
FarsiNumberToWordsConverter - promote arrays to fields to reduce allocations
Move ToOrdinalWords method to INumberToWordsConverter
EnglishNumberToWordsConverter - refactoring
Introduce DefaultNumberToWordsConverter which just returns string representation of a number
minor cleanup
restructuring Localisation folder a bit