Update to latest vanilla-rtb ( simplified bidder assembly ) and include extensions

[venediktov]

• point framework submodule to the latest vanilla-rtb stack
• include new submodule http://gitHub.com/vanilla-rtb/extensions
• try generating matchers from stubs by vanilla-rtb-extensions generator
• for extra credit try generating cmake and http_bidder.cpp file

All generated code should land into github.com/vanilla-rtb/rapid_bidder/bidder_experimental