Add a styled and mostly content-complete about page.

Add:
        static/js/about.js, static/sass/(index, about).sass
                -Minor cleanup before merge into `develop`: remove a superfluous
                style rule, update header comments.

Add:
        templates/about.html, static/sass/about.sass
                -Add text to the about page, and the necessary styling for it.

        app.py, templates/layout.html
                -Add an automated copyright year loader.

Add:
        templates/about.html, static/js/about.js
                -Add a `speed` attribute to all image divs, which is used to
                determine the rate at which an image moves upward.

        static/img/about/bg2.png
                -Change image to another source-code screenshot.

Conflicts:
	bitshift/crawler/crawl.py
	bitshift/languages.py

Add:
        static/sass/main.sass
                -Rework the footer, which is now fixed at the bottom of the
                screen as opposed to floored to the bottom of the page.
                Positioning at the bottom of the page doesn't make any sense
                with a technically infinite results page.

Add:
        static/sass/about.sass
                -Clean up existing style rules.
                -Add rules for the about sections' text.

        templates/about.html
                -Integrate with `templates/layout.html`, the project's global
                HTML template.

Add:
        templates/index.html, static/(sass/about.sass, js/about.js, img/about/)
                -Add first iteration of the about page, with basic parallax
                scrolling and filler text.

New commits in `feature/style` address various issues.

Add:
    templates/index.html, static/(sass/index.sass, js/index.js)
        -Add hotkey help div, which fades in whenever the `?` hotkey is pressed.

Add:
    static/js/index.js
        -Suppress hotkey (`h`, `j` `k`, and `l`) events when the keys are
        entered in text input-fields.

Add:
    templates/index.html, static/(js/index.js, sass/index.sass)
        -Add error messages for failed queries.