Adding LambdaBlock DSL for Java 8 lambdas

[ghost]

Hey @qmx! I've added a simple DSL block for generating lambdas more easily, mostly because I find the multiple invokedynamic arguments required for lambdas is tough to get my head around.

In a nutshell, lambdas require the following:

• Functional interface type, method, and signature
• Optional specialization of the functional interface method signature
• The number and types of the arguments to capture off the stack
• The method to delegate the lambda to

Using this information, the relevant invokedynamic instruction is created to delegate into the implementation method.

Caveats:
The lambda block test (JiteClassTest#testLambda) is only run on Java 8. The test method exits if not running Java 8. I've taken steps to ensure Java 8 isn't required when using jitescript by coding all JDK 8 class names as strings. Is there a better way to manage the test given the JDK version constraint? :S

Examples:

• JiteClassTest#testLambda
• Lambda for partial function application
• Lambda for curried function

[qmx]

wow, this is amazing @lmcgrath \o/

Will merge soon(ish), thanks!

[ghost]

Woohoo!