Adding some support for require syntax in Aria Templates tests.

A future version of Aria Templates will integrate noder-js and
allow the use of require in any module (when using the new syntax).
This commit makes attester compatible with the use of this
new syntax inside tests.
It is needed because, before this commit, attester extracted
the classpath from a test file by executing that file in a special
environment (containing a fake Aria.classDefinition method to extract
the class definition, but with no require function available). This
is no longer possible with the new syntax, and adding a fake require
function to that special environment would not be easy.
The new algorithm, which is only used when the new syntax is detected,
parses the file with Uglify-JS and extracts the required information
(classpath of the current class and logical path of the parent class),
without executing the file.
In case the file is detected to be a test suite, extending directly
from require("ariatemplates/jsunit/TestSuite"), only the constructor
function is executed, in a special environment, to get the classpaths
of the tests included in the test suite.