Changed error handling in Catalog Upgrade path to cleanly exit the
server with a descriptive error message irrespective of the type of
failure detected in the upgrade attempt.

One new path identified is where a stored procedure in the catalog is
loaded but the initialization code of that class generates an exception
or throwable. In the test case the class throws NoClassDefFoundError and
we don't detect or recover from the throwable gracefully.

This patch also changes the catalog diff test to use crashLocalVoltDB
instead of an assert.
ENG-6268 Added text to make it clear on Size Worksheet that VARCHAR columns are measured in UTF-8 characters
Fix JUnit tests that rely on previous error output
Minor documentation correction
Incorporated Comments from Steve and Paul
Merge branch 'master' of github.com:VoltDB/voltdb into ENG-6268
ENG-6268 Added text to the sizing chart to make it clear that VARCHAR columns are measured in UTF-8 characters by default.
Merge pull request #1364 from VoltDB/ENG-6177-ErrorOutputOnCatalogUpgrade

Eng 6177 error output on catalog upgrade
Merge pull request #1366 from VoltDB/ENG-6268

ENG-6268 Added text to sizing chart to make it clear VARCHAR measured in UTF-8 characters
ENG-6100 voltadmin update with catalog or deployment omitted.
ENG-6100 Tweak the help message based on review.
Merge pull request #1368 from VoltDB/notest-ENG-6100-voltadmin-update

ENG-6100 voltadmin update with catalog or deployment omitted.