Provide an option that enables JFR

[apurtell]

Provide an option that launches HBase daemons with the Java Flight Recorder active, with continuous profiling, including allocations (requires custom JFR policy xml), with dump on exit active to well known paths. Also should turn on

-XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints

for better fidelity when profiling methods. See http://hirt.se/blog/?p-609