Fix intial pageload headers, new array methods & diacritics functions

* The initial pageload html is now sent using "res.send()", which also
  sets the needed headers, as opposed to "res.end()", which only sends
  the body, and is only used for json strings

* The Array prototype has 2 new methods:
  - difference: to get all the values of the first array that are
                not in the second.
  - exclusive: to get all the values that are in the first or in
               the second array, but not in both.

* The String prototype has 3 new methods:
  - romanize: remove all diacritics (accents) from the string.
  - diacriticPattern: get a string that can be used as a regex
                      pattern which will mach all possible
                      diacritic variations.
  - diacriticRegex: the same as above, but return as a new RegExp