1. Renamed StringExtensions.Match() method to IsMatch()

2. Added new extension methods and classes :
- NumericExtensions: Abs()
- AssemblyExtensions
- BooleanExtensions
- DateTimeExtensions: DownTo(), UpTo()
- StringExtensions: Drop(), IsBoolean(), IsDateTime(), IsDouble(),IsGuid(), IsInteger(), IsIpAddress(), IsUri(), Matches(), Multiply()
- UriExtensions: Host()

3. Added missing XML docs comments

4. Updated README.md documentation file