Added objectives to swc-python files-list ipython notebook
Add key points to swc-python file-lists ipython notebook
Added figures for lists, organized list section.
Adding figures for list references.
Add field names to the database tables

Helps with understanding which data is retrieved by the queries
Add image to illustrate join
Changes after field testing this summer
DOC fix image path in 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
add TOC for README.md
DOC add lost swc-shell images from swcarpentry/guide repo

	new file:   lessons/swc-shell/absolute_path.png
	new file:   lessons/swc-shell/command_shell.svg
	new file:   lessons/swc-shell/decwriter.jpg
	new file:   lessons/swc-shell/direct_shell_usage.png
	new file:   lessons/swc-shell/filedir_challenge.png
	new file:   lessons/swc-shell/find_file_tree.png
	new file:   lessons/swc-shell/google_vs_grep.png
	new file:   lessons/swc-shell/nano.png
	new file:   lessons/swc-shell/nano_quotation.png
	new file:   lessons/swc-shell/permissions_table.png
	new file:   lessons/swc-shell/process_stdin_stdout.png
	new file:   lessons/swc-shell/public_private_keys.png
	new file:   lessons/swc-shell/relative_path.png
	new file:   lessons/swc-shell/remote_shell_usage.png
	new file:   lessons/swc-shell/running_a_process.png
	new file:   lessons/swc-shell/running_wc.png
	new file:   lessons/swc-shell/running_wc_sort.png
	new file:   lessons/swc-shell/running_wc_sort_head.png
	new file:   lessons/swc-shell/shell_as_process.png
	new file:   lessons/swc-shell/shell_on_shell.png
	new file:   lessons/swc-shell/x_for_directories.png
Merge pull request #46 from r-gaia-cs/css

Solve issue #44
Spelling and capitalization consistency
DOC update `order` variable in `lesson\swc-shell\tutorial.html`
DOC update lessons' link of index.html
Adding a figure to the database filters lesson
Merge pull request #70 from HaveF/swc_shell_lost_temple

DOC add lost part(intro) to the swc-shell
Merge pull request #78 from HaveF/first_page_link_update

DOC update lessons' link of index.html
Add explanation for "no output behavior" of cd
Add additional heading, move 'no output box' down a bit
removed aggravating comma