first attempt at a new student lesson
fixed some formatting and grammer errors
proposed replacement for shell-overview
Fixed the copious spelling errors
fixed 'grant_proposal' directory errors
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
DOC base on #81, copy swc-shell images for ipynb

	new file:   lessons/swc-shell/files/absolute_relative_path.png
	new file:   lessons/swc-shell/files/filesystem.png
	new file:   lessons/swc-shell/files/home_directories.png
	new file:   lessons/swc-shell/files/vlad_homedir.png
Importing lessons on Git
Adding John Wilbanks quote
Suggested fixes for lessons/swc-git/tutorial.md
Fixing intro and backup lectures on Git for novices
Revising (shortening) Git intro for novices
Starting work on glossary
Added hint illustrating modulo operator
Changed order of exercise, coersion paragraph
Added pandas slides
Added exercises to Pandas notebook