Update SelectorFormat linter to allow selector-specific conventions

Change-Id: Idac3447646ee5a2bfeee4bea8cbaa5ff2f27bfe1
Reviewed-on: http://gerrit.causes.com/43625
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>
Update changelog with new SelectorFormat options

Change-Id: Ie8ba7d62678f3f61e47eb74e76635745b7296473
Reviewed-on: http://gerrit.causes.com/43626
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>