Extensible agent

- Possibility to extend agent easily
- Updated Java-version to 1.5
Visibilities

- Added visibility for MetricParams and MetricParamsSigar to extensions
- Added fix to pom.xml to make it work without errors in eclipse
Visibility for exception

Changed InvalidPerfMonMetric to public
Eclipse specific part removal

- Removed configuration that prevented eclipse's errors.
Tests added

Added tests for new classes, and brought powermock in to help testing.
Removed Eclipse's extra files
Eclipse files to .gitignore
Back to Java 1.4

- Java.version back to 1.4
- Removed powermock
- Added jUnit back to pom
- New resource directories to include ServiceLoader -files (src and
test)
- Cleaned mocks out of tests
Extending old ones

- If extension uses same metric type that has been used previously, it
checks all services before throwing error up
- Added logging to service.
Logging cleaning

- No error message when service is checking different providers
- When metricProvider not found, error thrown with all classes tried
(dropped logging level from error to debug at implementations)
- Getter for metricParams to allow extensions to use parameters, too
Merge pull request #1 from Hi-Fi/master

Possibility to extend perfmon-agent easily