[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.