Fix for issue 5 - 'ignorecase' flag

https://github.com/Twinside/vim-haskellFold/issues/5
Changed eval-=~ operator to eval-=~#, because latter ignores 'ignorecase' flag. This way lines, starting with 'Module' are not considered separate fold.
Haddock header is now correctly folded
![ignorecase_bug_fix](https://cloud.githubusercontent.com/assets/5804169/3004395/40232846-dd98-11e3-9aa6-e12b1c9f6c8d.png)