Fix lthiv instantitate test so it runs
Clean up naming in analysis_view in preparation for bigger refactorings.
Fix currentView, which was broken by the analysis_view cleanups.
Quad was missing dependency on base
Begin normalizing namespaces

The namespaces we use dont match the directory structure. This tries to clean that up.

Details are in #699.

This moves tracing to tv.core, then ensures that all of extras/ is in tv.e.
Hoist palleteProperties to actual variable
Move test_utils back to core
Rename tv.core to tv.c
Bulk rename
Fix trace_viewer after base namespace change
Remove import-time dependency on polymer constructor. At this point, its not knowable
After loading tests, wait for polymer ready before running tests.
Move from tv.b.onPolymerReady to Polymer.whenReady
Update README.md
Remove raster_task_sub_view. It was not discoverable-enough to warran the complexity.
Now that old raster task subviews are gone, simplify naming of remaining view
Split apart extension registry
Add utilities for working with the global Polymer element list.
Move AnalysisView to use simpler extension model

BUG=#692

Previously, AnalysisView had this registry designed to allow a small number of
components to handle a wide variety of model types. This was done by
associating both a 'supportsSelection' and 'viewConstructor' function with each
component, plus a priority. We would then walk all registered types until a
match was found. This technically worked but was quite hard to understand and very non normative.

This patch changes analysis over to a simpler model: the selection is blown
apart by event types as before. But, the types are handled by a known sub-view
component: slices by the slice sub view. There are different components for
singule selections versus multiple: one slice gets a single-slice-sub-view, two
or more slices selected gets the multi-slice-sub-view.

This model is only as extensible as the trace_model itself. If new trace model event types are added, then the event list needs to be updated and new types of default components added. This actually feels a bit logical, which suggests that we're on the right track.

Some of the sub-views are extensible. Extensibility is the job of that
sub-view.
Improve upon tab styling a bit