Miscellaneous improvements and bug fixes.
added missing 's' to wikilinks documentation
Merge pull request #272 from cjrd/master

added missing 's' to wikilinks documentation
Merge pull request #266 from ryneeverett/issue52

miscellaneous issue52 improvements
Updated footnote documentation for clarity.

This addresses a misunderstanding reported in issue #273. The behavior has not changed. The docs just better reflect the actual behavior better. Apparently using the word "definition" both for footnotes and definition lists was an unfortunate coincidence that created confusion. We now use the term "footnote content".
Fixed silly spelling errors.

Must remember to spellcheck everything I type.
Add feature for emphasizing some lines in a code block.

A code blocked headed by “:::python{1,3}” now emphasizes the first and third lines. With fences enabled, ```python{1,3} has the same effect.
Fixed parsing of brackets within inline image titles.
Merge pull request #275 from geekman/master

Fixed parsing of brackets within inline image titles
Support syntax for highlighted lines like: ```python hl_lines=“1 3”
Allow single as well as double quotes for hl_lines.
Document hl_lines feature for fenced_code and codehilite extensions.
Merge pull request #274 from ajdavis/highlight-lines

Add feature for emphasizing some lines in a code block.
Address various depreciated APIs in Python

This mostly revolves around old APIs for ElementTree, but includes a few
others as well. Fixes #254. Thanks for the report.
Only escape ESCAPED_CHARS.

Leave all other chars prefaced by a backslash alone. Fixes #242.
Not sure why I thought that I needed to add another backslash.
Thanks for the report and the test case @mhubig.
No longer percent encode spaces in urls.

The current implementation was wrong as it also percent encoded query strings
(which should be plus encoded) and calling urllib.quote on the path (and
urllib.quote_plus on the query string) assumes the url is not already encoded.
What if the document author pasted a url that was already encoded? She probably
did not intend for `%20` to become `%2520`. Or did she? It is now clear to me
why many implementation do nothing to urls. Just pass them though as-is. To bad
if they are not valid HTML. HTML authors have to encodee their own urls, so I
guess markdown authors have to as well.