Change old instrument field names

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Disable Graoumf Tracker loader

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
[test] Add DigitalTracker loader test

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Update changelog

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>