checkbox text filter weird results

[Timo-Breumelhof]

Yes, I know this will not be fixed, I'm just logging this so someone else with this issue does not "burn" 2.5 hours of debugging like I did..
On an existing project with this version of jpList I noticed that the filter results using the Checkbox-text-filter were incorrect.
After a lot of testing I found that the results are incorrect when the value contains a hyphen (-)

This does not work correctly:

```
<div
	   class="jplist-group"
	   data-control-type="checkbox-text-filter"
	   data-control-action="filter"
	   data-control-name="keywords"
	   data-path=".keywords"
	   data-logic="or">


	<input
		  value="nature"
		  id="nature"
		  type="checkbox"
	   />

	   <label for="nature">Nature</label>

	   <input
		  value="grade-2"
		  id="grade-2"
		  type="checkbox"
	   />

	   <label for="lifestyle">Grade-2</label>
	</div>

This does:

		```
<div
		   class="jplist-group"
		   data-control-type="checkbox-text-filter"
		   data-control-action="filter"
		   data-control-name="keywords"
		   data-path=".keywords"
		   data-logic="or">


		<input
			  value="nature"
			  id="nature"
			  type="checkbox"
		   />

		   <label for="nature">Nature</label>

		   <input
			  value="grade_2"
			  id="grade-2"
			  type="checkbox"
		   />

		   <label for="lifestyle">Grade-2</label>
		</div>

So I simply replaced the - with _ (is an option in my use case) and the filtering worked correctly