cherry picks for 0.17.4

[johnynek]

Bring all the binary compatible changes from develop into 0.17 branch

binary compatibility checked:

[info] scalding-core: found 0 potential binary incompatibilities while checking against com.twitter:scalding-core_2.11:0.17.2
[info] scalding-avro: found 0 potential binary incompatibilities while checking against com.twitter:scalding-avro_2.11:0.17.2
[info] scalding-hadoop-test: found 0 potential binary incompatibilities while checking against com.twitter:scalding-hadoop-test_2.11:0.17.2
[info] scalding-repl: found 0 potential binary incompatibilities while checking against com.twitter:scalding-repl_2.11:0.17.2
[info] scalding-json: found 0 potential binary incompatibilities while checking against com.twitter:scalding-json_2.11:0.17.2
[info] scalding-db: found 0 potential binary incompatibilities while checking against com.twitter:scalding-db_2.11:0.17.2
[info] scalding-hraven: found 0 potential binary incompatibilities while checking against com.twitter:scalding-hraven_2.11:0.17.2
[info] execution-tutorial: previous-artifact not set, not analyzing binary compatibility
[info] scalding-jdbc: found 0 potential binary incompatibilities while checking against com.twitter:scalding-jdbc_2.11:0.17.2
[info] scalding-parquet: found 0 potential binary incompatibilities while checking against com.twitter:scalding-parquet_2.11:0.17.2
[info] scalding-commons: found 0 potential binary incompatibilities while checking against com.twitter:scalding-commons_2.11:0.17.2
[info] scalding-thrift-macros: found 0 potential binary incompatibilities while checking against com.twitter:scalding-thrift-macros_2.11:0.17.2
[info] scalding-parquet-scrooge: found 0 potential binary incompatibilities while checking against com.twitter:scalding-parquet-scrooge_2.11:0.17.2
[success] Total time: 12 s, completed Dec 19, 2017 9:46:39 AM

cc @FlavSF @moulimukherjee @snoble @pankajroark

Will publish 0.17.4 after this is merged.

[CLAassistant]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 4 committers have signed the CLA.

:white_check_mark: moulimukherjee
:white_check_mark: johnynek
:x: FlavSF
:x: snoble
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[ianoc]

lgtm

[johnynek]

releasing 0.17.4