Use a 3,4 split for Greek mobile numbers

- according to http://www.itu.int/dms_pub/itu-t/oth/02/02/T02020000550001MSWE.doc, the formatting for mobile numbers
  follows a 3,4 split. e.g. +30 693 XXX XXXX
- this is also how mobile numbers are listed in the Non-geographic numbers section of the wiki http://en.wikipedia.org/wiki/Telephone_numbers_in_Greece
Merge pull request #200 from tpena/enhancement/Greece-mobile-splitting

Use a 3,4 split for Greek mobile numbers
Adapted Slovenian rule matching based on ITU and Twiki info

Page 1 of the ITU document http://www.itu.int/oth/default.aspx?lang=en&parent=T02020000BE indicates the
possible structures of the National (Significant) Numbers. We used this information, with the focus on
mobile numbers, to fix up the parsing rules. Furthermore, the maximum length of the NSN is 8 digits whic
meant that the previous parsing rule (fixed(2) >> split(3, 2, 2)) would not return the correct plausibility
results for valid numbers.

Added plausibility as well as formatting specs.