fix(jqLite): next() should return the sibling element

[Keyamoon]

nextSibling() returns a text node. By replacing it with nextElementSibling(), issue #1730 would be fixed.

Example showing wrong behavior: http://jsbin.com/exosoz/1/edit

[pkozlowski-opensource]

@Keyamoon Could you add tests, change commit message and sign CLA as described here:
http://docs.angularjs.org/misc/contribute

[petebacondarwin]

This is a valid issue.

As @pkozlowski-opensource says, it needs unit tests to demonstrate the issue - preferably in a separate commit before the fix so that it is easy to check that the tests fail before the fix is applied.

[Keyamoon]

Alright I made another pull request with separate commits: #1732

Closing this one.