Better alignment with LoggingEvent

I thought it would be more aligned with Log4Net filtering if the source property were set to the LoggerName (commonly implemented as the declaring type where the logger is called).

Additionally, the time should be the time from the logging event.
Type set to the logger level (since source contains the LoggerName)
Removed unused static declaration.
Updated for Log4Net Nuget Reference.
Clean up not found assembly references in the 1.2.10 project.
Clean up unused using statements.
Target .NET 4.5 consistently in the 1.2.10 project