Fix recording of running operator stats

They were not being merged properly into the operator summaries for the pipeline
Add live visualization for query execution

This can be accessed via the "execution" link in the query details UI
Fix typo in JMX connector documentation
Allow reading/writing sequences of pages with mixed block types

The current implementation causes problems when a single remote request
gets multiple pages that have different encodings for a given column. This
could happen, for example, if the stream is the result of a union of
subqueries or tables that produce different types of blocks for any given column.

The reason is that the identifier for the block encodings is written once per request
based on the encodings of the first page. This fix changes the wire serialization format
to include the block encodings for each page in the response.
Set context class loader when creating ORC writer

The ORC memory manager ends up loading VersionInfo which loads classes
from the context class loader. The tests now set an empty class loader
to verify that it uses the correct class loader.
Add favicon for UI
Add scheduled flag to query info
Only show progress in UI when scheduled
Merge remote-tracking branch 'upstream/master'