Don't consider `$` as part of Scala identifiers.

'$' are implementation specific, but can appear in legitimate programs as escape
sequences in interpolated strings. Hyperlinking should only consider the identifier
without '$' signs. 

Fixed #1001408
Merge pull request #417 from dragos/issue/fix-interpolation-hyperlinking-1001408

Don't consider `$` as part of Scala identifiers.