Also changed pom to keep java 1.7

Conflicts:
	com.amd.aparapi/src/java/com/amd/aparapi/internal/kernel/KernelRunner.java

file moved to com.amd.aparapi/src/main/java/com/amd/aparapi/internal/kernel/KernelRunner.java

Conflicts:
	com.amd.aparapi/src/java/com/amd/aparapi/internal/kernel/KernelRunner.java

dispose() disposes of the jniContextHandle, however the seenBinaryKeys still reported that the handle is still available. This resulted in a kernel being unable to recompile after any of it's predecessors have been disposed. Clearing this set fixes this issue.

Correct reported getLastConversionTime()

Resolve exception in kernel.dispose()