Simplify the API

[cdornan]

The API will be further simplified, reducing the amount of modules the user needs to consider while keeping them (as they are) quite small and simple, with the aim of reducing the cognitive load on the developer using the package top write some code.

• Rename Internal to ZeInternals to get them dropped to the bottom of the Hackage page, not the top.

• Move the Text.RE.TDFA.RE (and Text.RE.PCRE.RE) modules to Text.RE.ZeInternals.TDFA (PCRE).

• Remove Text.RE.Types and move all of the the Text.RE.Types.* modules under
  ZeInternals, except

  • IsRegex, which becomes Text.RE.IsRegex.
  • REOptions which becomes Text.RE.REOptions;

• Establish the following interface:

  • Text.RE.Replace.

• Move Text.RE.TestBench under Text.RE.ZeInternals and convert
  Text.RE.TestBench.Parsers into the API module at Text.RE.TestBench.