Optimizing Eventsource memory allocations and removing an extra comment.

[JRahnama]

This PR is addressing Issue#92 and Issue#681.

• Issue#92 regarding // call OnError outside of _ErrorCollectionLock to avoid deadlock comment, apparently the lock is moved inside a function called GetFullErrorAndWarningCollection to avoid deadlocks. comment is safely removed.

• Issue#681: This is a first step of making EventSource optimized. all ToString() methods are removed from eventsource related code implementation, if possible, and moved inside EventSource class inside the if checkers to see if the log is requested, for perf improvement. all arguments passed to NonEvent functions are checked for null values and null-coalescing operator is applied inside EventSource class.

New methods have been added to EventSource class overloads. This methods do not have the IsEnabled checker inside them. They are used when IsEnabled is called out of EventSource class, for instance when a setup was needed to make one or more variables to be passed to EventSource functions. These methods have the bare name such as TraceEvent etc.

Older methods in NonEvent overloads region of EventSource class, the one with IsEnabled checker inside, a prefix of Try is added to the old names to distinguish between two different kind of overloads.

There were places that log levels, such as "INFO' or "API" and etc. as a separate string to the string.Format method, I have combined those two strings to be one and use a different overload from EventSource.
At some places while using null coalescing the log message was passing a string containing "null" or "", in possible cases I have removed them as the null checker is applied inside EventSource class.

[TrayanZapryanov]

I leaved several comments.