Tests for Core::Route.

Moves and extends what was t/route.t into the new class based structure.
Mark route tokens for capture with regex comments.

Aligns the way regexp comments are used for token, splat and megasplat.
The substituted captures for token and splat are very similar..
Rework route match for mixed token and splat captures.

With all the regex captures now flagged with comments, we iterate over
the captured values knowing if they were from a token, splat or megasplat.

Added examples of mixed token ans splat capture to the route matching
tests.

Resolves #514.
reflect change
Merge branch 'feature/mixed_named_params_and_splats'