ZEPPELIN-1094: Run all paragraphs keeps appending empty paragraph.

ZEPPELIN-1130: Make Livy create session retries configurable.

ZEPPELIN-1143: Interpreter dependencies are not downloaded on zeppelin start.

ZEPPELIN-1146: Zeppelin JDBC interpreter should work in a Kerberos environment.

ZEPPELIN-1149: %sh interpreter kerberos support.

ZEPPELIN-1159: Catch RestTemplate exception.

ZEPPELIN-1166: Change the jquery-ui CSS file name.

ZEPPELIN-1168: Add http header X-Requested-By in post request to Livy Interpreter.

ZEPPELIN-1175: AM log is not available for yarn-client mode.

ZEPPELIN-1199: Need to login using keytab and principal before creating SparkContext in secured cluster.

ZEPPELIN-1212: User impersonation support in JDBC interpreter for Hive.

ZEPPELIN-1242: Should set property SPARK_YARN_MODE and do login before creating any spark stuff.

ZEPPELIN-1305: Fix bug of ZEPPELIN-1215.

ZEPPELIN-1319: Use absolute path for ssl truststore and keystore when available.

ZEPPELIN-1320: Run zeppelin interpreter process as web front end user.