Properties, period parameter

🗞 In this release:

• Added period parameter that sets server's buffer size.
• Made publicly set server and driver parameters — properties.
• Added available_drivers attribute.
• Fixed segfault that was caused by to unnecessary _destroy() call. This was appearing when _destroy() was called manually (not in __del__()).
• Refactored working with C pointers, now they're initialized only once.

Full Changelog: v0.0.3...v0.0.4