Convert dates to JVM timezone before storing in H2
Change QueryAssertions to make it easier to add a breakpoint
Remove test query comparisons with DATE literals

Not all connectors support dates and instead use VARCHAR.  This means that a test
query can not assume the column is a DATE.
Bump airlift and tpch versions to non snapshot versions
[maven-release-plugin] prepare release 0.87
[maven-release-plugin] prepare for next development iteration
Use version 6.1.1 of checkstyle library

The version used by the checkstyle maven plugin doesn't support Java 8,
so override it manually until the plugin is fixed
Add utility for bridging Guava builders with Java 8 streams

This allows us to do the following and get an ImmutableList or ImmutableSet:

List<Integer> list = collection.stream()
    .map(...)
    .filter(...)
    .collect(ImmutableCollectors.immutableListCollector());

Set<Integer> set = collection.stream()
    .map(...)
    .filter(...)
    .collect(ImmutableCollectors.immutableSetCollector());
Minor improvements to ImmutableCollectors

- Rename methods to toImmutableList and toImmutableSet
- Simplify method signatures
- Remove unnecessary type specification for lambda args
- Declare set collector as UNORDERED to give stream implementation
  more room for optimization
Implement ImmutableCollectors.toImmutableMultiset
Deprecate IterableTransformer
Enable modernizer plugin

For now, start with the stock set of violations and only warn.
Change Travis config to use Java 8
Reduce memory footprint in Travis
Don't fork compiler

This speeds up compiling by ~25% and helps prevent Travis from running
out of memory
Load java.* classes from parent classloader
Convert Accumulator to take a BlockBuilder
Implement arbitrary aggregation function
Fix an issue when using row_number() and limit() together
Fixed a minor issue with the 0.80 release notes