Benchmark and compare optimizations

[MelGrubb]

Set up benchmark tests, and test the effect of some basic optimizations.

• Try a readline-based approach to splitting strings in the XML documentation processing. See https://stackoverflow.com/a/23408020/1763 for some examples of alternative string-splitting approaches. Especially look at https://www.meziantou.net/split-a-string-into-lines-without-allocation.htm and see how it compares.
• Compare string constants vs. embedded resources for code templates.
• Extract strings or resource loading to a template object, similar to the "csharp" class from the past. This can be the extensibility point for Support custom templates #32