Rewrite visualize.js to use existing url parser

This also changes the nesting of the checking for the different supported paths
(the old version had some at the top level, and some in the catch all "else"
branch - very strange).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
If we have no datasets for the requested timeframe, skip it.

Otherwise the update could simply 'hang'.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make streaming.js more robust

The test for existance appears to cause database issues. I need to investigate
why, but for now let's just store multiples.

Also avoid a few more potential errors when the servers are down.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Improve the robustnes of the AJAX updates

Report failures, prevent infinite looping if there are gaps in the data.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>