[BUGFIX] In-memory columnar storage bug fixes

Fixed several bugs of in-memory columnar storage to make `HiveInMemoryCompatibilitySuite` pass.

@rxin @marmbrus It is reasonable to include `HiveInMemoryCompatibilitySuite` in this PR, but I didn't, since it significantly increases test execution time. What do you think?

**UPDATE** `HiveCompatibilitySuite` has been made to cache tables in memory. `HiveInMemoryCompatibilitySuite` was removed.

Author: Cheng Lian <lian.cs.zju@gmail.com>
Author: Michael Armbrust <michael@databricks.com>

Closes #374 from liancheng/inMemBugFix and squashes the following commits:

6ad6d9b [Cheng Lian] Merged HiveCompatibilitySuite and HiveInMemoryCompatibilitySuite
5bdbfe7 [Cheng Lian] Revert 882c538 & 8426ddc, which introduced regression
882c538 [Cheng Lian] Remove attributes field from InMemoryColumnarTableScan
32cc9ce [Cheng Lian] Code style cleanup
99382bf [Cheng Lian] Enable compression by default
4390bcc [Cheng Lian] Report error for any Throwable in HiveComparisonTest
d1df4fd [Michael Armbrust] Remove test tables that might always get created anyway?
ab9e807 [Michael Armbrust] Fix the logged console version of failed test cases to use the new syntax.
1965123 [Michael Armbrust] Don't use coalesce for gathering all data to a single partition, as it does not work correctly with mutable rows.
e36cdd0 [Michael Armbrust] Spelling.
2d0e168 [Michael Armbrust] Run Hive tests in-memory too.
6360723 [Cheng Lian] Made PreInsertionCasts support SparkLogicalPlan and InMemoryColumnarTableScan
c9b0f6f [Cheng Lian] Let InsertIntoTable support InMemoryColumnarTableScan
9c8fc40 [Cheng Lian] Disable compression by default
e619995 [Cheng Lian] Bug fix: incorrect byte order in CompressionScheme.columnHeaderSize
8426ddc [Cheng Lian] Bug fix: InMemoryColumnarTableScan should cache columns specified by the attributes argument
036cd09 [Cheng Lian] Clean up unused imports
44591a5 [Cheng Lian] Bug fix: NullableColumnAccessor.hasNext must take nulls into account
052bf41 [Cheng Lian] Bug fix: should only gather compressibility info for non-null values
95b3301 [Cheng Lian] Fixed bugs in IntegralDelta
(cherry picked from commit 7dbca68e92416ec5f023c8807bb06470c01a6d3a)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>