Fix false assumption about scheduled basals from diasend

The original blip processing code was written under the assumption that it would have a continuous stream of scheduled basal segments.  That is not true for diasend and the logic that was associating the edges of scheduled basals was doing things wrong.  This fixes it to rely on the durations provided in the events, 'cause those are correct.
allow navigation to device settings page
fine-tuning device settings interaction
handle navigate to most recent and refresh when on device settings page
Merge branch 'master' into jebeck/device-settings
Merge pull request #50 from tidepool-org/jebeck/device-settings

add device settings page to display most recent/current insulin pump settings
Merge branch 'master' into cheddar/fix-basal-associations
Merge pull request #49 from tidepool-org/cheddar/fix-basal-associations

Fix false assumption about scheduled basals from diasend
Merge branch 'master' into cheddar/use-join-key
device settings page makes Most recent button active since settings are always most recent for now