Use $eval instead of $apply in loadTemplate()

the current loadTemplate() can't be used in the callback of load() because of the scope.$apply() phase check
Add onload&$includeContentLoaded event for template

Also remove the $eval & $evalAsync on the function(). Because $eval will just simply return the pass-in parameter function. Remove them to save CPU cycles
Fix the bug on the onload expression
Merge pull request #2 from dreamershl/master

Use $eval instead of $apply in loadTemplate()