Go SDK needs to enforce minima for discovery intervals and default for full discovery

[ctyanke]

The Java SDK now enforces the following discovery intervals when it parses the probe-conf.xml file:
Full Discovery (rediscovery-interval-seconds) must be >= 60. Also, if no rediscovery-interval-seconds is specified in the xml, use default value of 600 seconds.
Performance Discovery (performance-rediscovery-interval-seconds) - if specified, must be >=60. If not specified the ProbeInfo should return -1 for getPerformanceRediscoveryIntervalSeconds().
Incremental Discovery (incremental-rediscovery-interval-seconds) - if specified, must be >=1. If not specified the ProbeInfo should return -1 for getIncrementalRediscoveryIntervalSeconds().