Use ValuePipe for Scalar2
cleanups + Either methods to the Typed-API
Merge pull request #628 from twitter/fix-scalar2

Use ValuePipe for Scalar2
Remove unneeded type parameter
Fix overrides
Fix comments, add some spaces
Merge branch 'develop' into either

Conflicts:
	scalding-core/src/main/scala/com/twitter/scalding/typed/ValuePipe.scala
Handle merges
Merge pull request #633 from twitter/either

cleanups + Either methods to the Typed-API
Allow plugging the joining algo, was needed for highly skewed matrices
Added TypedCsv, TypedPsv and missing method to typed TypedTsv.
Moved TypedDelimited sources into a separate file and added TypedOsv.
Merge pull request #634 from twitter/matrix2-cleaner

Allow plugging the joining algo, was needed for highly skewed matrices
Merge pull request #632 from stephanh/more_typed_sources

Added TypedCsv, TypedPsv and missing method to TypedTsv.
keep out log4j dependency since slf4j backend should be decided by application not library (also its already on hadoop classpath and slf4j complains when multiple versions of backend are detected on classpath)
Merge pull request #636 from tresata/feat-no-log4j-deps

keep out log4j dependency since slf4j backend should be decided by appli...
Prefer to use sumOption to take advantage of algebird optimizations
Make LzoTraits extend TypedSink and LocalTapSource.
Merge pull request #638 from azymnis/lzo_trait_typed_sink

Make LzoTraits extend TypedSink and LocalTapSource.
Merge pull request #637 from twitter/sumOption

Prefer to use sumOption to take advantage of algebird optimizations