Add support for partial match in Interpolation patterns

[danielo515]

Hello.
Thanks for this family of libraries, really streamline the development of Haxe.
Something that I think may be useful is to support partial matching of interpolation patterns.
Some way to flag that you don't care about the start or end of the rest of the string. For example

switch input {
  case 'Hello, $who...': trace(who);
  default:
}

and for Hello, Danielo Rodriguez it will match Danielo and discard the rest.