added very basic classpath resource loader

doesn't yet support scanning, but still a step forward
Added basic support for defining a root package when loading from classpath

ClasspathResourceLoader may now receive a root package in Ctor to load
resource from.
eg:
loader = new ClasspathResourceLoader("com/testing");
loader.load("mytemplate.html"); //can find com/testing/mytemplate.html
Merge pull request #206 from stefcl/master

added very basic classpath resource loader