Added option for delimiter filtering

[DirkBaumeister]

Hey, I needed an option to filter multiple keywords by delimiter. For example:

Values:

• Item 1 / Category 1
• Item 1 / Basket 2
• Item 1 / Test 3

Now, if I tried to search for 'item category' for example there was no result.

Now, if you enable the option enableDelimiterFiltering this kind of search is possible.

Additionally you can specify the delimiter for this kind of filtering by the option filterDelimiter.

The default is ' '.