Update 'compile' section to work with Angular 1.3.0

When using Angular v1.3.0-beta.17 and attempting to place selectpickers inside a Kendo UI TabStrip, I received errors which basically eluded to the fact that event data wasn't present. While I couldn't track down the precise cause of the error, I eventually solved the problem by reworking the compile section (I introduced a 'postLink' function in place of the plain return [may be unnecessary]). I discovered that, at least in my scenario, removing the entire 'ngModel.$render' function not only stopped the errors but still allowed the pickers to work perfectly, inside and outside of the Kendo TabStrip. Obviously, this removal is subject to review, since the @joaoneto authored it to be there. Perhaps there are changes with Angular 1.3.0 that allow a simplification of this directive? Even if my code structure isn't acceptable, I request the review of the removal of the ngModel.$render function.
Update angular-bootstrap-select.js
merge refer #11