Parses segmented string expression and converts it into a Regexp

  Strexp.compile('foo')
    # => %r{\Afoo\Z}

  Strexp.compile('foo/:bar', {}, ['/'])
    # => %r{\Afoo/(?<bar>[^/]+)\Z}

  Strexp.compile(':foo.example.com')
    # => %r{\A(?<foo>.+)\.example\.com\Z}

  Strexp.compile('foo/:bar', {:bar => /[a-z]+/}, ['/'])
    # => %r{\Afoo/(?<bar>[a-z]+)\Z}

  Strexp.compile('foo(.:extension)')
    # => %r{\Afoo(\.(?<extension>.+))?\Z}

  Strexp.compile('src/*files')
    # => %r{\Asrc/(?<files>.+)\Z}