Refactor: Moved 3 helpful private functions from GenderDetectionBenchmarks.java to Helper class as public methods.

- 	public static String normalizeVowels(String string)
-	public static String normaliceAsciiChars(String string)
-	public static String removeNonAlphabeticChars(String string)
Refactor: from 1 overlord Helper to 6 different helpers:

- CollectionHelper
- FileHelper
- JsonHelper
- StringHelper
- ParamsHelper
- WebHelper
FeedReader class revision (now it does work, there was a bug with the resultant file that make impossible to read from Weka tool)
Removed the category named "ECONOMIA" from AvaibleCategories enum and Category class.
FeedReader.java: just some JavaDocs
TextClassifierExample: updated to the not - existence of ECONOMIA category
Minnor improvement in StringHelper: In normalize(text) it put an extra white space at the beginning of the response; not anymore
Spanish very first stop list (as .txt file)
Minnor changes in FileWriter and ArffWriter.

Added some useful functions such as: isComment(line), isEmpty(line) etc
New src folder "fileUpdater" which updates an old arff file and calls normalization to each data line
Updated 3 arff files: 28, 29, 30 (april 2014)
Merge remote-tracking branch 'origin/dev' into dev