We can be unprecise a bit by using a hash of table to represent a state of
optimizer thread, after all any collision will result in just a shorter prefix search.
Replace following names:
std.typetuple -> std.meta
TypeTuple -> AliasSeq
ParameterTypeTuple -> Parameters
FieldTypeTuple -> Fields
std.traits requires more work than search/replace and is left unchanged.
The docs and API still stay in one file.
With time and refactoring more internals may be
exposed such as parser, each engine explicitly
and the sample generator (generator.d).
Also inclusdes changes prompted by reviews/pulls:
Convert spaces-->tabs in makefiles.
Move things (again) to std/regex/internal.
Use new package(std.regex) feature.
Remove C-style arrays (some other pull against regex.d).
