Backported ID Methods from 0.2.1

Made PactString appendable

Added setters for file statistics for easier subclassing

Generified binary and sequential i/o formats

added test-jar goal to pact-tests pom

Decreased waiting times in IPC Client and JobManager to speed up LocalExecutor

Fixed size of memory manage of mini cluster to 1/4 of available heap
The previous method of using the freeMemory fails for rapid successions of unit tests because not all memory is immediately freed by GC and thus successive starts of the mini cluster will result in ever decreasing sizes of the memory manager.

Generalized methods in format utils

Fixed incorrect handling of generic formats in data sink tasks

Change-Id: I46210d017bdb0339d10db0b5304a1f8367a8cd8d