Enable G1 garbage collector
Enable G1 garbage collector

* operate concurrently with applications threads
* compact free space without lengthy GC induced pause times
* more predictable GC pause durations
* better throughput performance
* not require a much larger Java heap

JIRA: FUEL-187
Change-Id: I42b95969613495d44d3ea1a4fcaae20ed01a26fb

stackforge/fuel-plugin-opendaylight,stackforge/fuel-plugin-opendaylight,stackforge/fuel-plugin-opendaylight,stackforge/fuel-plugin-opendaylight