some more unittests and some fixes
doc fixes
doc fix MrSmith33
Array problem
stupid me

stupid me
The getter for Logger.logLevel now uses an `atomicLoad` instead of full mutex lock.
Read-access to `stdlog` is now back...
Fixed inverted DDoc meaning for `isLoggingActive`.
Removed synchronization with a global lock for the duration of any standard logging call in an exchange of sequential consinstency for throughput.
Rejects valid: logf(LogLevel.fatal, "I am %s", true);
(The template constraint is not required in this case.)
Fix for `template isLoggingActive` that would break if an actual log level was disabled.
MultiLogger rewrite