remove boolean response for zerohttp
add metrics jar
move transaction_id class from ed
add slf4j logger and improve metrics
cleanup
fix jar load path
add tracker
Merge branch 'master' into zerohttp

Conflicts:
	lib/liquid/metrics.rb
	liquid-ext.gemspec
small tracker cleanup
expose metrics reporting interval
minor fixes
make Timing return nano seconds
report timestamp too
add support for additional metric dimensions
integer precision is enough
add guava and trove
report every 5 minutes by default
tableize exception classes in metrics
log metrics every 60 seconds