Added new set of material for a R only bootcamp

This material is based on @karthikram's bootcamp that was held in Canberra.
added notes on documentation.
Added notes on documentation addresses issue #112, renumbered sections.
Removed numbering both for sections and exercises within.
Simple vectorization examples in numpy
Start of new Git Intermediate lessons

This Introduction borrows heavily from characters, concepts, and prose
from git/beginner/00-intro.md by @gvwilson.
using context manager in files tutorial
started data.table demo
Added first part of Conversational Git section.

(Also, some cleanup to introduction, and added index)
migrated Leszek's changes to strings-io/tutorial.ipynb
merging in Leszek's changes to gh-pages

Thanks to @czterybity for this contribution, and to @wking for
mentoring this pull request.

Thanks to @r-gaia-cs, @mattphotonman, @gvwilson, @wltrimbl, and
 @ethanwhite for helpful commentary and feedback.
updated data.table demo, added .md file
Add %pylab magic so ntoebooks run with plain ipython notebook without pylab=inline argument
fixed Will Trimble attribution
fix IPython capitalization
some suggested fixes to the thw-python vars-types exercises
Merge pull request #195 from gvwilson/gh-pages

Changing month name in YAML header to make it clear that we prefer 3-letter abbreviations.
Changing month name in YAML header to make it clear that we prefer 3-letter abbreviated forms
Merge branch 'gh-pages' of github.com:cliburn/bc into cliburn-gh-pages
Fixes to Cliburn Chan's vectorization lessons