Some changes made to tests (configuration partially moved to separate file)
Added pake/{transactions,packages}/__pycache__/ directories to `clean`
rule in Makefile
Added some dummy files for tests
Test for package pushing written; bug in pake.node.pusher._lsdir() for FTP servers not supporting MLSD fixed (was always listing current working directory)
Preparation for networking-related tests and another major refactoring