Update Curry highlighting to version 0.2

In response to the tips I got on the Kate developer mailing list,
I updated the highlighting to version 0.2. This version is now integrated
into the official kate repository, so that you can also download
the Curry highlighting via

  Configure Kate -> Open/Save -> Modes & Filetypes
  -> Down Highlighting Files ...

New features:

  * Escape sequences in Char and String literals are recognized
  * Char literals of illegal length (0, > 1) are marked as syntax errors
  * Illegal escape sequences are marked as syntax errors
  * String gaps are recognized and handled
  * Parentheses, brackets and braces open/close a corresponding region