fix($compile) remove call to trim when processing attributes

BREAKING CHANGE: This change could cause applications to fail if they rely on
whitespace in attributes to be stripped out. For example, if prior to this
change you used the ng-model directive like so:

    <input ng-model="mymodel ">

then after this change this binding would fail.

This change is required by certain directives (such as ng-list) that require
their attributes to be unmodified.
test(ngList) Add test for list seperators with whitespace