fix(compile): should not leak memory when there are top level empty text nodes

The change to prevent <span> elements being wrapped around empty text nodes caused these empty text nodes to have scopes and controllers attached, through jqLite.data() calls, which led to memory leaks and errors in IE8.
Now we exclude all but document nodes and elements from having jqLite.data() set both in the compiler and in ng-view.

Fixes: #1968 and #1876
fix(ngClass): keep track of old ngClass value manually

ngClassWatchAction, when called as a $watch function, gets the wrong old
value after it has been invoked previously due to observation of the
interpolated class attribute. As a result it doesn't remove classes
properly. Keeping track of the old value manually seems to fix this.

Closes #1637
fix($compile): sanitize values bound to a[href]
docs(changelog): add release notes for 1.0.5 and 1.1.3
chore(release): cut 1.1.3 radioactive-gargle release
docs(changelog): fix release notes
feat(ngTap): add ngTap directive for fast clicks on touch devices

Add a new module ngMobile, with mobile/touch-specific directives.
Add ngTap, equivalent to ngClick but using touch events, which are much
more responsive on mobile.