[SPARK-10973][ML][PYTHON] Fix IndexError exception on SparseVector when asked for index after the last non-zero entry

[zero323]

See #9009 for details.

[jkbradley]

This patch includes updates to a lot of pom files. Can you please remove those?

(Thanks for sending all of these backports, btw!)

[SparkQA]

Test build #1874 has finished for PR 9062 at commit 962e1ab.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[zero323]

@jkbradley Should be OK now.

[SparkQA]

Test build #1879 has finished for PR 9062 at commit c209b5f.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[jkbradley]

I'll wait for the test to finish, but regardless, I'll merge this into branch-1.3. I tested it locally, and it worked.

[SparkQA]

Test build #1884 has finished for PR 9062 at commit c209b5f.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[jkbradley]

Merging with branch-1.3
Thanks for all of the patches!