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.
Fixes issue #21

fixes issue #12
Added the messy data file. Fixes #11
Fixes #6
closes #5
closes #4
closes #1
closes #2
Converted best_practices to Rmd
fixes #7
Updated ignore list

This will stop folks from accidentally committing rendered markdown files to the repo.
Replaced with Rmd files
Removed old split-apply.
Updated R basics

Addressed all comments raised by Gavin and John on this section. I moved individual items to issues which you can see here:

https://github.com/karthik/bc/issues?state=open
Signed-off-by: Karthik Ram <karthik.ram@gmail.com>
Removed extra file

Signed-off-by: Karthik Ram <karthik.ram@gmail.com>
Updated material on functions

Everything is now converted to Rmd from md.

Signed-off-by: Karthik Ram <karthik.ram@gmail.com>
Updated section on data manipulation

Now all sections are executable code blocks

Signed-off-by: Karthik Ram <karthik.ram@gmail.com>