Download package addon is now downloading, validates checksum, unzips th...

...en adds to the application repo.

Improvements to the server stubs to provide a zip file.
Additions to the tests rig for easier testing
How about moving FileSystem related code to BaseLibrary? so code will be 
<BaseLib>.CreateDirStructure([...]) # this will throw exception 
<BaseLib>.SafeCreateDirStructure([...]) # this wont throw exception and but return True  or False (may be cleanup created dirs)