Scalding repl and library usage get lots of love

• REPL: Add toIterator (and related methods): #929
• Fix the build to use the shared module method: #938
• Clean up the UniqueID stuff, to avoid plumbing it everywhere: #937
• TypedPipe.from(List).distinct fails: #935
• Clean up ExecutionContext a bit: #933
• Fix Issue 932: no-op Jobs should not throw: #934
• Use Execution to run flows in REPL: #928
• Snapshot a pipe in the REPL: #918
• Add support for AppJar in Config: #924
• Fix LzoTextLine as a TypedSource: #921
• Use externalizer in BijectedSourceSink: #926
• Add an Executor to run flows without a Job: #915
• This handles the case where scalding will save out a tsv and re-use it down stream leading to issues where the types are not strings: #913
• Fix DailySuffixTsv for testability, remove leaked DailySuffixTsv: #919
• Add a Config class to make configuration understandable: #914
• Integrate the repl completely into scald.rb. Fixup scald-rb for better hdfs-local mode now with our provides: #902
• Add some auto-reformats: #911
• Update JDBCSource: #898
• Allow tests for typed delimited by fixing swallowed bug: #910
• Add Hadoop platform test to enable unit testing for Hadoop semantics: #858
• Some minor improvements to typed joining code: #909
• Fix #906: #908
• Run the test target, so the tests are reformatted: #907
• Enable scalariform: #905
• Simplify "scald-repl.sh": #901
• Typed Tutorial: #897
• Adding a test for the scalding repl: #890
• Properly close tuple iterator in test framework.: #896
• Add constructors to ValuePipe: #893
• contraMap and andThen on TypedSink/TypedSource: #892
• Tiny fix to use an ImplicitBijection rather than Bijection: #887
• Feature/bijected source sink: #886
• Fix intersection equality error: #878
• Add DailySuffixTypedTsv and HourlySuffixTypedTsv.: #873
• add stepListner register support in Scalding: #875
• Backport Meatlocker: #571