Added Scala support to engine.R
Created Markdown example calling R, Scala, Python and Bash, each performing string shuffling
Added Scala support to engine.R
Added Scala support to engines.R.
Merge pull request #640 from ElderResearch/master

Added Scala support to engines.R
news for #640
the method defaults$get(name, drop=FALSE) should preserve the names if they do not exist instead of making them NA

e.g. list(x=1)['y'] returns something like list(NA=NULL) instead of list(y=NULL), and we need the latter

fixes a bug reported by Frank Harrell in the mailing list http://bit.ly/17yitsD
bump version
I mean 2 here; a previous test modified the default value for a
the asis engine also uses options$eval, per suggestion of Kirill
multiline support for haskell thanks to @aavogt (PR #633)