version for 8/18
Revert "version for 8/18"

This reverts commit fd4f4554fb71005097a0b4d80d05cebca7b79ba7.
Merge remote-tracking branch 'twruser/master'
resolve #51
resolve ggvis
shift these 2 packages to suggests
resolve #46
resolve #25
move whisker and ggvis to Suggests since they are not important
Merge branch 'master' of github.com:wush978/DSC2014Tutorial
Merge remote-tracking branch 'twruser/master'
Merge pull request #52 from wush978/master

resolve dependency issue and implement Basic_file
add data.table package into DESCRIPTION / close #57