Testing suite

First, i've added testing script (for now): `3test.sh` (although it's a python script, will rename it). This script just sequentially run zvsh with different arguments. It's much convenient to immediately see test results, also no need to worry about timeout.

Plans about it:
+ I plan to make this script use daemonized zerovm (already started, with no success, actually)
+ To make some sort of quicktest and fulltest testing
+ Use its return code as signal about current python state (for Jenkins)

Next, i began to modify python test suite. Some tests use unsupported features and should be skipped. I'm adding `skipIf` conditions all over the tests. Python `sys.platform` is a good indicator.
Moreover, it much more cleaner to test against particular features (like `hassattr(module, function)`), but we have some issues with making our custom toolchain + zrt + autoconf work as I suppose them to work.