Change StandardError to RuntimeError

Since built-in exception "StandardError" does not exist in the latest python version (at least in version 3.3), use RuntimeError instead (which exists from python2.6 to python3.4)
docs/plugins.rst: fix signal name "page_generator_context"

The old "pages_generate_context" dates from before pelican-3.2
standardization, but AFAIK, "page_generate_context" was never correct.
Merge pull request #1119 from jedbrown/jed/fix-signal-name-doc

docs/plugins.rst: fix signal name "page_generator_context"
Fix #1117 Make intra-link support all url-value HTML attributes.
Fine-tune url-value HTML attributes list.
Merge pull request #1123 from calfzhou/intra-link

Fix #1117 Make intra-link support all url-value HTML attributes.
Clarify FAQ entry re: need to install Markdown

Folks keep running into this error, which probably signals a need to
change this behavior. After all, it wouldn't be hard for us to detect
what's going on and provide a better error message, such as: "It looks
like you're trying to process Markdown, but the Markdown library is not
currently installed. Please install the Python-Markdown library via 'pip
install markdown'."

Until we implement something akin to the above, this should serve as a
slightly-improved FAQ entry in the interim.
Merge pull request #1118 from yapbreak/patch-1

Change StandardError to RuntimeError
use // instead of explicitly defining http

for twitter as well

update sample output
Merge pull request #1132 from fly/disqus_ssl

use // instead of explicitly defining http
Document video support in Markdown and reST.
Merge pull request #1129 from kdeldycke/markdown-youtube-tip

Document video support in reST & Markdown.
Improve Disqus embed code in notmyidea theme

According to Disqus, the disqus_shortname variable is a required field.
Also added a <noscript> notice for those who have JS disabled.
fix #1116, pages are not generated in version 3.3.0

- declare default content directory to PATH in pelicanconf.py template
- Removing references to INPUT_DIR from Makefile template
fix #1116, pages are not generated in version 3.3.0

- declare default content directory to PATH in pelicanconf.py template
- Removing references to INPUT_DIR from Makefile template