Reduce Verbosity of Type Names by using Nested Namespaces

[LK-Simon]

I'm going to switch the library from using verbose type naming (e.g. ThreadGarbageCollector) to using a Nested Namespace.

For example, ThreadGarbageCollector will instead become GarbageCollector belonging to the Threads sub-namespace under the ESPressio parent namespace.

Therefore, to directly address the GarbageCollector class, the markup would be:

ESPressio::Threads::GarbageCollector

This may look like more code, but proper use of namespaces will in fact reduce the complexity of your code.

[LK-Simon]

Completed in a7511b1