Fix parentheses

Fix humantime check to correctly handle 12:XXam/pm in 12hr format

* Hours run 12, 1, ..., 11 in 12hr time (12:00pm follows 11:59am)

Added link to Configuration Problems / Solutions

using find -exec to remove temporary files

1) avoid problems with spaces
2) avoid messages when no file is found

consolidate badge classes to swc.css

Minor change to have the same look of lessons

Improve editor instructions

Thanks to @iglpdc for report it.

Move instructors section from setup/index.md to CUSTOMIZATION.md

Rewording suggested by @ethanwhite.

Figures should be centered
and not overflow the screen.

-   Move editor's instructions to after Git.
    This avoid the "nano is the editor installed
    by the Software Carpentry Installer".
-   Make a more uniform suggestion of another editor
    that learners can use, i.e.
    mention SublimeText in all platforms.
-   Others minor rewording.

Close #183.

Close #169.

The information at the web pages should target students.
Information for instructors should go into CUSTOMIZATION.md.

make basestring workaround more obvious

Adding a 'root' variable to allow pages in sub-directories.

@karawoo recently created a workshop website with a sub-directory for syllabus material. The `_layouts/page.html` template didn't work properly in this case because our included files have fixed relative paths to CSS and JS files. This PR adds the `root` variable, and references to it, where needed. It also moves the inclusion of `footer.html` to the right place (so that the footer spans the whole page).

Note that the `index.html` page already had an (unused) `root` variable.

git-scm.org doesn't seem to reliably point people at an installer
based on their OS version, rather it seems to use the most recently
built installer [1].
So it's probably best to explicitly send people to the git-osx-installer
downloads and tell them which one to grab.

[1]: https://github.com/swcarpentry/workshop-template/pull/204#issuecomment-93172064

Everyone else should download a "snow-leopard" installer.

Replace '<code>nano</code>' with 'nano'

The project refers to itself as "SQLite" [1], and none of these
references are suggesting command-line invocation.

[1]: http://www.sqlite.org/