[C149_E] Refactored to recursive Disemvoweler

  - Inspired by Wiezy_Krwi's solution:
    http://www.reddit.com/r/dailyprogrammer/comments/1ystvb/022414_challenge_149_easy_disemvoweler/cfnfu63
  - Uses recursive Disemvoweler to make one pass through the string instead
    of calling String.collect on the input twice
  - Uses ListToString to convert a list of chars to a string by use of a
    System.Text.StringBuilder: http://stackoverflow.com/a/18596756
[C149_E] Fixed Disemvoweler by reversing output to match function call.
[C149_E] Refactored Disemvoweler to an Array.fold function.
[C149_E] Cleaned up Array.fold accumulator by specifying tuple value names.