gitignore: Added to ignore list debuild's garbage
Tests: Restructurization

Separated cache-specific test case to separate binary.
Added ability to specify remote nodes for dnet_cpp_test.
tests: Report tests result at detail level
tests: Added automatic srw_test
Client: Make session to store only weak-reference to node
Core: Fixed memory leak of namespace
Client: Removed guardians around elliptics node in session

It leads to several bugs when node can be destructed from the
io thread.
tests: Implemented Cocaine integration tests
Client: Removed checks for node from session
tests: Fixed segfault in srw_test

Don't destroy server node anywhere except atexit
Merge pull request #293 from euroelessar/master

Tests restructurization & changed session's contol over the node