Hides or shows the options of 1 or more select element(s) depending if they
match or not what is typed in an input field.

Requires doTimeout plugin :
http://benalman.com/projects/jquery-dotimeout-plugin/

Usage : $('#input').searchOnSelect($('#select1,#select2'));

Options available (and their default values) are :

options : {
    autoSearch true,
    flags: 'i',
    prePatternFormat: function(pattern) {
        return pattern;
    },
    preSearchFormat: function(search) {
        return search;
    },
    strict: false,
    type: 'and'
}

* autoSearch if true and a value is set in the input when the plugin is
initialized, it will automatically do a search on it when it's loaded.

* flags are the ones accepted by the RegExp constructor that is used when a
search is made. See the RegExp documentation for possible values.

* prePatternFormat is a callback method called just before using the pattern and
to make changes on it (removing diacritics for example).

* preSearchFormat is a callback method called just before using the elements to
search on and to make changes on it (removing diacritics for example).

* strict changes the way the search behaves :
    - If true, will search for the presence of the pattern.
    - If false, will search for the presence of the words (separated by spaces).

* type also changes the way the search behaves if strict is false :
    - If 'and', will search for the presence of all words.
    - If 'or', will search for the presence of at least 1 of all words.