Support importing Tumblr

Try to integrate Tumblr's various post types without using
additonal templates.
Fix importing Tumblr photo caption

Besides each photo's caption, the general caption is also needed.

While we're at it, also add a linefeed at the end of file.
Use better titles than None for Tumblr posts without title
Merge pull request #873 from xlz/tumblr-import

Support importing Tumblr
Support Gaug.es analytics in notmyidea theme
Add fabfile generation to pelican-quickstart

This commit adds optional fabfile.py generation during the
pelican-quickstart process. Reasons include:

* "make" is cumbersome to install on Windows
* Fabric runs in any Python environment
* fabfile is just Python and thus more flexible and extensible

This is an initial implementation and does not currently provide as many
upload options as its Makefile counterpart.

Refs #584.
Fix file endings for examples

reStructured should use reStructured for linked documents. Markdown should use Markdown for linked documents.
Merge pull request #986 from TheHippo/patch-1

Fix file endings for examples
Add documentation for WITH_FUTURE_DATES

Closes #952
added THEME_STATIC_DIR setting

The theme static output directory path is now customisable via settings.
i.e. you can now use 'assets' instead of 'theme'.