Added SPECIALSXP
function importr() to import R packages almost like they
were Julia packages.
Fixed the examples to match the recent changes.
Fixed 2D vector conversion by switching ndims() to size() and updated doc example to match code.
Merge pull request #26 from slundberg/master

Fixed 2D vector conversion by switching ndims() to size() and updated README
Merge remote-tracking branch 'upstream/master'
fix to make it compile on Mac Darwin OS X