Implementation of the monkey testing idea.

Create BlockSequence with one of following keywords:

• blocks - runs all blocks once with respect to their probabilities
• all - run all possible block combinations. Ignores block probabilities
• some(n: Int) - run blocks n times (works like for-loop or repeat for now)

Each block is executed with a particular probability:

• block - 100% probability (always executed)
• usually - 80%
• sometimes - 20%
• rarely - 5%
• chance(p: Double) - execute with a probability of p (in range 0..1)

You can change probabilities of block execution in Configuration class

It is possible to intercept a block call by adding an Interceptor. Method intercept(block: Block, isRan: Boolean) is called on each following block, regardless of whether it is ran or not (parameter isRan shows just that).