Added special highlighting of unused, non strict comparison and ++/--

As you suggested (#15) I took a stab at it, but instead of using near, which only matches the first word, and can cause problems with multiple occurrences of the word or symbols like ==/!= etc I modify the column information.

I am keeping the existing behaviour, but for the 3 cases it will provide a better highlighting.

This is how this implementation will look now on this example case: 
![highlight-2](https://f.cloud.github.com/assets/230877/1910004/97cd3ba6-7d0b-11e3-8768-7c0ae327e05e.png)


    function unusedfunc() {}

    function test(unusedarg) {
      var unused = { //missing use strict and unused
        extracomma:5, //extra comma
      };
      var anothervar = 5;
      if (5 == 4 && 5 == 3 && 4 != 5) {
        anothervar++;
        anothervar--;
      }


      with(window){
        return;
      }

      if(true){} //empty block
    }

    test() //missing semicolon


This was run with this jshintrc.


    {
        "bitwise": true,
        "curly": false,
        "eqeqeq": true,
        "forin": false,
        "immed": true,
        "latedef": "nofunc",
        "newcap": true,
        "noarg": true,
        "noempty": true,
        "nonew": false,
        "plusplus": true,
        "regexp": false,
        "undef": true,
        "strict": true,
        "trailing": false,
        "asi": false,
        "boss": false,
        "debug": false,
        "eqnull": false,
        "es3": true,
        "esnext": false,
        "evil": false,
        "expr": false,
        "unused": true,
        "funcscope": false,
        "globalstrict": false,
        "iterator": false,
        "lastsemic": false,
        "laxbreak": false,
        "laxcomma": false,
        "loopfunc": false,
        "multistr": false,
        "onecase": false,
        "proto": false,
        "regexdash": false,
        "scripturl": false,
        "smarttabs": true,
        "shadow": false,
        "sub": false,
        "supernew": false,
        "validthis": true,
        "browser": true,
        "couch": false,
        "devel": false,
        "dojo": false,
        "jquery": false,
        "mootools": false,
        "node": false,
        "nonstandard": false,
        "prototypejs": false,
        "rhino": false,
        "wsh": false,
        "nomen": false,
        "onevar": true,
        "passfail": false,
        "white": false,
        "maxerr": 100
    }