Rewrite API to support both dynamic and classic

The Roslyn compiler used by the current ScriptCs version does not support
dynamic C#. To make FakerOfData work with ScriptCs we must provide a
non-dynamic version of the API. This is done with methods that does not
expose anything dynamic which can be called from ScriptCs.
Add tests for RandomThings class
Add unit tests for the Some class
Create Common project

The common project should contain implementations of common random value
generators which are not considered as core functionality.
Add generator of strings based on a pattern

The generator supports

- Static text
- Character classes using square brackets
- The posix character classes :digit:, :alpha:, :alnum:, :upper: and
  :lower: