youtube/vimeo/video tag improvements

- Allow more flexible video identifiers, current one "\w" blocks e.g.
youtube identifier "ul-FqOfX-t8". New one allows also attaching
positional arguments to video, e.g. "ul-FqOfX-t8#t=123"
- Surrounded each video element with a div having "videobox"-class for
styling purposes (e.g. center alignment)
- improved code formatting
Fixes #193 Adding TEMPLATE_PAGES to tipue_search plugin
Fix outdated link to Pelican docs
Merge pull request #194 from Futurile/template-pages-search

Add TEMPLATE_PAGES to tipue_search plugin. Fixes #193
[tipue_search] Restore support for Python 3
Merge pull request #230 from Schnouki/patch-1

[tipue_search] Restore support for Python 3
Merge pull request #207 from jojanaho/master

Liquid tags: youtube / vimeo / video improvements
PLUGIN_PATH setting has been replaced by PLUGIN_PATHS and it should be a list
Merge pull request #233 from 2xyo/master

Migrate Readme.rst documentation to PLUGIN_PATHS
[post_stats] Python 3 compatibility

In Python 3, `filter()` returns an iterator instead of a list, which causes an error on line 42: "object of type 'filter' has no len()". Using a list comprehension fixes this, and is probably a little more readable.
Merge pull request #234 from Schnouki/patch-2

[post_stats] Python 3 compatibility
Properly encode author in comments
Merge pull request #235 from jml/master

Properly encode author in comments
added plugin descriptions table
[pelican_comment_system] Properly encode metadata

Related to #235
Merge pull request #237 from arty-name/descriptions

Add plugin descriptions table to README
fix invalid name for __init__.py & add unicode_literals import
Make touch plugin touch files with lists
Merge pull request #240 from idyedov/update_disqus_static

fix disqus_static plugin
Fixed: Gzip header should not contain filename. This causes error with some clients.