Update v2.1.5 - Bug-Fix Release

Fixed Bugs

• #15 restored target frameworks to netstandard1.6;net35;net40;net45;net46;net6;net7

Update v2.1.4 - Bug-Fix Release

Fixed Bugs

• #13 added missing null pointer check

Update v2.1.3 - Bug-Fix Release

Fixed Bugs

• #13 CalendarPeriodCollector collecting periods by day hours does not respect the limits period.
  New test CalendarPeriodCollectorTest.CalendarPeriodCollectorDayHoursWithLimitsTest()

Update v2.1.2

Changes

• added target framework .net 7

Bug-Fixes

• Fixed get relation of empty ranges #10
• Fixed time period subtractor ignoring the combine periods parameter #12