Filtering by notEquals raises "TypeError: Cannot read property 'equals' of undefined"

[alex-dev]

[x ] bug report
[ ] feature request
[ ] support request

Plunkr Case (Bug Reports)
http://plnkr.co/edit/ko1TUjDqwi98UtnMx7Tt

Current behavior
It is impossible to filter with filterMatchMode set to notEquals. Trying just raise an error due to trying to access equals of an undefined this.

Expected behavior
Filter the data table and show only rows not matching the value.

Minimal reproduction of the problem with instructions
Choose a value from the dropdown and look at the console.

• Angular version: 4.1.3

• PrimeNG version: 4.1.0

[alex-dev]

Just made a PR fixing the problem in the simplest way I could find.
#3389

[ctrl-brk]

From the docs: Default match mode is "startsWith" and this can be configured using filterMatchMode property of column object that also accepts "contains", "endsWith", "equals" and "in"
So, strongly speaking it's not a bug.

[alex-dev]

"Defines filterMatchMode; "startsWith", "contains", "endsWidth", "equals", "notEquals" and "in"."

And by me, a functionality in the code, not marked anywhere as non-functional, should work. Also, considering I fixed the bug and submitted a PR... The issue can be pretty much closed as soon as the PR is merged back.