Generalized ur strings
Changed ur strings of Python 2 to standard strings for Python 3
(Python 3 standard strings are unicode strings)
Discard use of % in favor of string.format()
Created xsls package to reorganize the project
Renaming of classes
XSLClearer is now developped only in Python 3
Oops, forgot CompilerException when discarding % in favor of format
Oops again for xslsclearer.py
Few little refactoring
Corrected bug: message attribute of CompilerException was not set
Added support for the special xmlns attribute
Bug in UnexpectedToken
Added short form for variable affectation
Made module names conform to coding standard
Added support for unnamed attribute when only one attribute is required
Forgot namespace before the variable tag
Improved error handling
Documentation update