Update metawidget-angular.js

In line 382, modified then ng-model attribute generation to account for the case when the attribute name starts with "[".
For example "[2].name"
Previously it always added a dot in front of the name so in case of an array it generated invalid attributes like:
"person.[2].name" which resulted in empty input boxes.
Merge pull request #22 from laszlothewiz/patch-1

Okay, let's do it your way :)

Thanks for the pull request. I'll take care of the test cases.