Add logging of the errors which asciidoc and asciidoctor output to their
stderr stream when converting asciidoc documents. Note that
asciidoctor's exit code may be SUCCESS even if there are ERROR messages
in its stderr output (tested with Asciidoctor 0.1.4 and 1.5.5).
Therefore log the stderr output whenever it is non-empty.
See #2399
Changes `%q` to `%s`. `%q` was safely escaping the `\` in windows so that it was printing `\\`. Uses `filepath.Join` for example filepath so that the output is OS specific and since this required splitting up the multiline string, it's refactored into a separate function..
Fixes#2401
Organize CSS and Javascript files into directories, separating vendor
source code from home-grown.
Separate new properties and selectors in Bootstrap CSS (already edited
for Hugo) from:
1. Original property values; and
2. Changed property values.
For the home page:
1. Clarify the English text;
2. Add some element names to classes in CSS selectors (to speed loading);
3. Document the Owl Carousel and Highlight.js versions;
4. Add Owl Carousel's license;
5. Restore HTML comments to browser source views;
6. Make the beginning GitHub button transparent on focus (like the others);
7. For the final, colored Twitter and Github buttons:
a. Remove the dotted box on focus; and
b. Color them green on active.
8. To increase (layout/) source readability:
a. Place `class` attributes before `href` attributes;
b. In `class` attributes, place more-specific class names before
less-specific; and
c. Comment the beginnings and ends of Bootstrap rows.
9. To increase understandability during development:
a. Document the meaning of CSS file, `HPstyles` by renaming it to
`home-page-style`;
b. Move inline styling to CSS stylesheets;
c. Separate @media queries to a file;
d. Separate the inline Owl Carousel custom Javascript to a file;
e. Use regular Owl Carousel CSS files instead of minified ones; and
f. Rename the wide, landscape desk background image filename from
`desk-long` to `desk-wide`.
