Nuked spurious ./tests directory

Only images, someone added a bit too much to the index
Fix for issue #219: tags should list only main articles, not translations
Fix webassets tests when running on a system with a different locale.
Merge pull request #810 from avaris/translations_in_tags

Fix for issue #219: tags should list only main articles, not translations
Merge pull request #809 from cdunklau/clean_up_images

Nuked spurious ./tests directory
Nitpicking - tempdir naming, also backslashes are bad

Tempdirs should have useful prefixes to aid in collecting information
    about failed tests.
Implicit concatenation is better than backslash line continuation.
fixed related_posts plugin
Merge pull request #813 from avaris/fix_related_posts

fixed related_posts plugin
Fix for issue #392
Merge pull request #819 from avaris/test-warning

Fixes issue #392
Merge pull request #807 from saimn/fix_webassets_tests

Fix webassets tests when running on a system with a different locale.
Added WordPress content decoding to importer
Implement Posterous import - fixes #608
Merge pull request #811 from cdunklau/clean_up_tests

Nitpicking - tempdir naming, also backslashes are bad
Add new option for controlling whether to display categories on menu or not

Conflicts:
	docs/changelog.rst
	pelican/tests/output/basic/tag/bar.html
	pelican/tests/output/basic/tag/baz.html
	pelican/tests/output/basic/tag/foo.html
	pelican/tests/output/custom/tag/bar.html
	pelican/tests/output/custom/tag/baz.html
	pelican/tests/output/custom/tag/foo.html
Merge pull request #578 from davidjb/display-categories-option

Add option to control displaying categories on menu
unify css class for pygments
Merge pull request #824 from avaris/markdown-css

unify css class for pygments
fix for issue #761: handle unicode correctly in summary for Markdown
Merge pull request #825 from avaris/markdown-summary

fix for issue #761: handle unicode correctly in summary for Markdown