librato output for metrics
use prefix in source for librato metrics
librato metrics improvements
set reasonable libratometrics_interval
include stream names in librato metrics
graylog2ctl improvements

now always has absolute path, no matter started from where - required for plugin file loading. now also stores log file in log/

fixes #SERVER-250
fix missing range in streamMessageCount()
removed forgotten debug output
first iteration of plugin installation

relates #SERVER-250
Update plugin-interfaces version in pom.xml
Replace throughput related methods with specific MessageCounter
Use new counter objects in MessageCounters
more possibilities in plugins
Merge pull request #107 from smasset/refactor-counters

Refactor counters
use recent graylog2-plugin
implemented MessageGateway.totalMessageCount()
messagecountermanager is overridden
Update graylog2-plugin version in pom.xml
Handle message timestamp instead of server current time
Formatting
 - convert tabs to spaces
 - remove trailing whitespace