[SPARK-9521] [BUILD] Require Maven 3.3.3+ in the build

[srowen]

Enforce Maven 3.3.3+ in the build. (Also update the scala compiler plugin while we're at it.)

[SparkQA]

Test build #39350 has finished for PR 7852 at commit 3093039.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • public static final class BytesToBytesMapIterator implements Iterator<Location>
  • public abstract class UnsafeKeyValueSorter
  • class SpecificUnsafeProjection extends $
  • abstract class UnsafeRowJoiner
  • |class SpecificUnsafeRowJoiner extends $
  • case class SortArray(base: Expression, ascendingOrder: Expression)
  • case class SubstringIndex(strExpr: Expression, delimExpr: Expression, countExpr: Expression)
  • public abstract class KVIterator<K, V>

[JoshRosen]

LGTM, especially given that we've run into problems with Maven versions in the recent past; better to fail-fast here.

[nchammas]

For the record, this PR is kind of a follow up to #6770.