Add mib generation for subscriptions
Add report propagation to SNMP manager

Test included which verifies that reports are received by the manager
and export disabling works as well.
Support SNMP inform for exometer reports

- adds export of all counter datatypes
- allows subscriptions to be exported over SNMP as inform messages
Fix unsecure generation of atoms and naming in SNMP example config
Use exometer_proc for reporters instead of custom protocol
Merge pull request #14 from Feuerlabs/tb-snmp-notifications

SNMP Export Notifications