add fenced_code extensions

This markdown extension support code block with tilde (```) syntax like github
Merge pull request #1 from lowstz/patch-1

add fenced_code extensions
fixed utf-8 support
Update requirements.txt

miss Flask-Login==0.1.3
Merge pull request #4 from lowstz/patch-2

Update requirements.txt
Added support for Windows machines
Added a clean_url operation to address common mistakes in url creation
Added capability to replace spaces with underscores and make everything lowercase.
Merge pull request #6 from traeblain/urlcleaner

Clean up url creation for new posts
Added support for custom title
Merge remote-tracking branch 'upstream/master' into windows
Updated Windows behavior to handle subdirectories properly
Added Delete confirmation prior to deletion. WARNING: Requires bootstrap.js and jquery.js
Updated sidebar index links to actually go somewhere
Merge pull request #10 from traeblain/htmlcleanup

Updated sidebar index links
Removed unminified jquery and bootstrap
Merge pull request #8 from traeblain/deleteconfirm

Added Delete confirmation prior to deletion
Merge pull request #7 from traeblain/wikititle

Added support for custom title
Added close button on the alerts.
Changed preview action to be a true preview, without savinging.