* Touch up readme info graphics

* Add layers to easily recreate the single steps
* Re-group objects
* Transform white rectangles for interrupting arrows into paths
* Adapt rectangle path forms to make arrow interruptions nicer
* Centre repository names in their repository boxes
* Add simple to hack to remove double rounded border problem in step 3
* Set background colour to white (was transparent before)
* Update repo cloning graphics to reflect changes in SVG file; optipng'ed
* Fix newline problems in repo cloning graphics SVG

* Remove superfluous newlines
* Add missing newline at end of file
Merge pull request #388 from stevenkoenig/fix-readme-info-gfx

Fix readme info gfx
Add link to older installers for Git for OS X

The current Git installer for OS X is broken for many pre-10.8
systems. The older installers seem to solve this problem.
Copy git lesson files as basis for hg lesson.
Port index and intro pages to hg.
Delete Git staging area image that has no Mercurial counterpart.
Delete image re: Git HEAD~* mapping to rev ids; unneeded for Mercurial.
Port the version control "A Better Kind of Backup" section to Mercurial.
Fix typos re: review by @r-gaia-cs.
First version of sklearn intro IPython Notebook
Removed lesson number
Added an outline

Also removed a cell
Print number of samples in the dataset
Use StandardScaler instead of scale

For simplicity just scale all of the dataset for
grid search.
see: https://github.com/swcarpentry/bc/pull/443#issuecomment-40677511
Optimize max_features instead of n_estimators

Useless to estimate n_estimators, the more the better!
Use a Pipeline to add feature scaling
README.md: Convert 'boot camp' -> 'workshop'

Following Amy Brown's [1]:

> We borrowed the "bootcamp" terminology from Hacker Within and also
> various fitness training camps, but as we branch out into parts of
> the world with a more violent recent history I'm less comfortable
> with the term.

The consensus on that issue was to change back to our old 'workshop'
terminology.  The swcarpentry/bc repository hasn't made the shift yet,
but there's no reason I can't embrace the future here ;).

[1]: https://github.com/swcarpentry/bc/issues/240
Merge branch 'master' into bc-namespaced

* master:
  README.md: Convert 'boot camp' -> 'workshop'