proposed replacement for shell-overview
Whitespace PEP8
Merge pull request #84 from wltrimbl/knightsrewrite

Simplified knights example to use straightfoward if instead of for...else.
Added explicit exposition on half-open nature of list indexes
Navigation notes for ipython
Markup prettify
Recited meanings of three fundamental data types.
Removed needless apology
Typos and markup in new sentences
Added line about print syntax
Fixed the copious spelling errors
fixed 'grant_proposal' directory errors
Changed GitHub URLs from SSH to HTTPS

In general, GitHub seems to prefer HTTPS over SSH, and they provide good
support to use it for read-only and read-write repositories on their
site.  In general, HTTPS is more fool-proof than SSH.  In this commit
I've replaced our root-level advice on cloning repositories with HTTPS
URLs.
revert tab completion to 'twice'
reinstate metadata
DOC move images under lessons/swc-shell/ -> img/lessons/swc-shell/

	renamed:    lessons/swc-shell/absolute_path.png -> img/lessons/swc-shell/absolute_path.png
	renamed:    lessons/swc-shell/absolute_relative_path.png -> img/lessons/swc-shell/absolute_relative_path.png
	renamed:    lessons/swc-shell/command_shell.svg -> img/lessons/swc-shell/command_shell.svg
	renamed:    lessons/swc-shell/decwriter.jpg -> img/lessons/swc-shell/decwriter.jpg
	renamed:    lessons/swc-shell/direct_shell_usage.png -> img/lessons/swc-shell/direct_shell_usage.png
	renamed:    lessons/swc-shell/filedir_challenge.png -> img/lessons/swc-shell/filedir_challenge.png
	renamed:    lessons/swc-shell/filesystem.png -> img/lessons/swc-shell/filesystem.png
	renamed:    lessons/swc-shell/find_file_tree.png -> img/lessons/swc-shell/find_file_tree.png
	renamed:    lessons/swc-shell/google_vs_grep.png -> img/lessons/swc-shell/google_vs_grep.png
	renamed:    lessons/swc-shell/home_directories.png -> img/lessons/swc-shell/home_directories.png
	renamed:    lessons/swc-shell/nano.png -> img/lessons/swc-shell/nano.png
	renamed:    lessons/swc-shell/nano_quotation.png -> img/lessons/swc-shell/nano_quotation.png
	renamed:    lessons/swc-shell/permissions_table.png -> img/lessons/swc-shell/permissions_table.png
	renamed:    lessons/swc-shell/process_stdin_stdout.png -> img/lessons/swc-shell/process_stdin_stdout.png
	renamed:    lessons/swc-shell/public_private_keys.png -> img/lessons/swc-shell/public_private_keys.png
	renamed:    lessons/swc-shell/relative_path.png -> img/lessons/swc-shell/relative_path.png
	renamed:    lessons/swc-shell/remote_shell_usage.png -> img/lessons/swc-shell/remote_shell_usage.png
	renamed:    lessons/swc-shell/running_a_process.png -> img/lessons/swc-shell/running_a_process.png
	renamed:    lessons/swc-shell/running_wc.png -> img/lessons/swc-shell/running_wc.png
	renamed:    lessons/swc-shell/running_wc_sort.png -> img/lessons/swc-shell/running_wc_sort.png
	renamed:    lessons/swc-shell/running_wc_sort_head.png -> img/lessons/swc-shell/running_wc_sort_head.png
	renamed:    lessons/swc-shell/shell_as_process.png -> img/lessons/swc-shell/shell_as_process.png
	renamed:    lessons/swc-shell/shell_on_shell.png -> img/lessons/swc-shell/shell_on_shell.png
	renamed:    lessons/swc-shell/vlad_homedir.png -> img/lessons/swc-shell/vlad_homedir.png
	renamed:    lessons/swc-shell/x_for_directories.png -> img/lessons/swc-shell/x_for_directories.png
DOC fix swc-lesson images' path after mv images to img\lessons\swc-shell

	modified:   _includes/guide-shell/create/lesson.html
	modified:   _includes/guide-shell/filedir/challenges.html
	modified:   _includes/guide-shell/filedir/lesson.html
	modified:   _includes/guide-shell/find/lesson.html
	modified:   _includes/guide-shell/intro/lesson.html
	modified:   _includes/guide-shell/pipefilter/lesson.html
extended python function lesson
- real life example for function stacks
- default parameter ordering
- why functions aid maintenance
typo
Added link to documentation on lists