Add support for activity splits

[nugget]

Add support for distance and heartrate splits when posting fitness activities to RunKeeper.

[nugget]

ergkeeper now submits detailed splits for both distance and heartrate when posting new fitness activities. However, the RunKeeper API currently only supports splits with actual latitude/longitude data, from which it calculates distance and pace. Since an Erg is stationary, this isn't an available option, so only the heartrate will show up on the runkeeper site.

Hopefully RunKeeper will add support for relative distance splits in the future and we can start supporting them at that time. Leaving this issue open, unresolved for now.

[nugget]

I found a support forum thread started by another application developer who is similarly blocked by this limitation in the RunKeepr HealthGraph API: https://groups.google.com/forum/?fromgroups=#!topic/HealthGraph/cqdcwsW4JgI