FromConfig 492
Correcting the FromConfig #492 bug for local actors.

Lacking tests for remote deployed actors still.
Added `FromConfig.Instance`

Actors w/o FromConfig removes router info from `Deploy` instane now
Move SerilogLogMessageFormatter to correct namespace.

This should have been made in #292 but we missed that.
It should be backwards compatible, sort of . As long as no
   using Akka.Logger.Serilog;
statement exists in files where SerilogLogMessageFormatter  is used everything should compile (with a warning that SerilogLogMessageFormatter  in the old namespace is obsolete).

If a both namespacese are used:
   using Akka.Logger.Serilog;
   using Akka.Serilog.Event.Serilog;
The user will get a compile error. The resolution is to remove the second using statement.
Add ReSharper external annotations to log methods in the Akka assembly

This makes ReSharper understand that for example log.Error's first parameter is a format string and that the method behaves just like string.Format()

For more info, see
https://www.jetbrains.com/resharper/webhelp/Code_Analysis__External_Annotations.html
https://www.jetbrains.com/resharper/webhelp/Code_Analysis__String_Formatting_Methods.html
Merge pull request #504 from HCanber/resharper-annotations

Add ReSharper external annotations to log methods in the Akka assembly
Merge pull request #503 from HCanber/serilog-fix

Move SerilogLogMessageFormatter to correct namespace.
Merge pull request #493 from rogeralsing/from-config-492

FromConfig 492
Added better typeresolution for config and serialization.

instead of checking type.gettype for null result, that is now handled in a helper method with a consistent error message.