This bug appears when an aggregate expression has a nested
expression. Previously it was only looking for an expression reference
and not a full expression.

Fixes #6363

The previous code had two issues. The first was a bug in using the
user-specified y-axis column for checking if a goal had been
met. Beyond that the pulse code didn't recognize those user specified
x and y axes either. This commit uses the user specified columns, when
they are not present defaults to the previous first/second column
behavior in the resultset.

Hydrating series dashcards wasn't including the related collection
id. The collection id is one way in which permissions are
checked. This would manifest itself in the user having access to
something they shouldn't. As an example, if a dashboard had a single
card that was part of a collection the user wouldn't have access to,
and the user attempted to access it, they would get a 403. If a second
card was added and that card contained multiple (i.e. a series) due to
this bug, the second card wouldn't have a collection_id and thus we'd
assume the user has access to it. The permissions checking on the
dashboard only checks whether or not the user has access to at least
one card in the dashboard, thus giving user access to the dashboard.

Fixes #5266

This commit adds code needed to query time fields and to filter by
time fields. Support is included for all database backends that
support time fields. Previously depending on the backend, the result
of querying a time field was either an exception or an incorrect
"zeroed out" date of 1970-01-01 followed by the time.

Fixes #5563, fixes #5829

Previously this was done by the frontend, including boolean that
enables it. This moves the logic to the backend.

This commit adds the backend pieces needed to attach CSV and XLS files
of query results to Pulses. Attachment support is also there for
Alerts. This is an opt-in feature for pulses and alerts. Users can
update existing Pulses to include attachments or add them to a new
pulse. The file(s) will only be attached when there are results.

Fixes #6587, fixes #3894, fixes #2623

This commit ensures nested queries include dimension options for
datetime and coordinate fields. Whether or not to include dimension
options is derived from the result metadata of the card.

Fixes #6166

Currently all :type/DateTime values, including :type/Date values are
serialized as ISO timestamps, which includes the time and
timezone. This commit handles :type/Date fields differently, emitting
only the date (year, month and day).

Fixes #5828

Some timezone abbreviations, especially non-US timezone abbreviations
aren't parsed by JodaTime. The SimpleDateFormat parser is more
flexible with these. This commit adds a SimpleDateFormat fallback to
the JodaTime formatters so if the JodaTime one fails, it will try
SimpleDateFormat ones next, hopefully figuring out what timezone the
database is in.

Fixes #6354, fixes #6085

Dependong on what timezone you're in, the system_time_zone can be
returned as abbreviated timezone identifier like CST or it can return
an abbreviated offset like -02. This commit adds some special handling
for the offset case.

Fixes #6483

Previously notifications weren't sent if an admin disables emails on
an alert. This commit will check to see if an updated alert had it's
enabled flag changed and will send unsubscribe or added notification
emails.

Fixes #6571

Flipping the argument order makes it easier to support multiple
datetime parsers via a varargs parameter.

Now whenever running migrate force, it will remove the MD5 checksums
in the databasechangelog table and recalculate them. This is mostly
useful for developers running code from several different branches.

Fixes #6372

Before this commit, via the `/database/:id/metadata`, we make a DB
call for each field's target table. On databases with a larger number
of these values, it can cause many database calls. This will fetch
them via batch hydration first, which will significantly reduce the
number of calls.