Fixed replacing reserved words.

I solved problem with uppercase queries.

Fixed:
"TIMBERLAND Men\`s" was converted to "TIMBERL&& Men\`s"
Do you mean something like

```php
$reservedWords = array('/\sAND\s/u' => ' && ', '/\sOR\s/u' => ' || ', '/\sNOT\s/u' => ' !');
$result = preg_replace(array_keys($reservedWords), array_values($reservedWords), $term);
```
?