Only show publish promo to users that can publish

In our no-results template, there's no point in displaying a "publish your first post" promo to users that don't have the ability to publish posts since they can't act on it.
Renaming inc/tweaks.php to inc/extras.php and including by default in functions.php
Use a filter for wp_title instead of hard-coding things in header.php
Rename translations to languages, see #73 and #50
Update README.md

Edited some typos and improved some phrases.
Merge pull request #83 from kovshenin/patch-12

Rename translations to languages, see #73 and #50
Merge branch 'master' of https://github.com/mjangda/_s into mjangda-master
Remove current_user_can() check from index.php. A similar conditional now exists in no-results.php.
Merge pull request #90 from hugobaeta/patch-1

Update README.md
Fixed typos in README.MD
Merge pull request #92 from iamtakashi/fix-typos-in-readme

Fixed typos in README.MD
Removed dangling pubdate attributes

The <time> attribute "pubdate" appears to no longer be part of the HTML5 spec, so remove them (they weren't being used anyways)
Change .tag-links to .tags-links

Using the class .tag-links may cause a rare formatting bug. To reproduce:

1. Publish a new post and tag it "links"
2. post_class() assigns the class .tag-links to the post
3. Any formatting applied to .tag-links in the theme's stylesheet will also apply to this post -- not good!

Changing the class name to something that won't conflict, like .tags-links, should solve this problem.
Merge pull request #94 from sixhours/patch-1

Change .tag-links to .tags-links so it doesn't cause an edge-case conflict with posts tagged as "links".
Added max-width to select elements in widgets to prevent it overflowing. This intends to fix a common issue - the dropdown in the category widget overflows when a blog has a long category name
Fixed small typo in README
Space before colon

Minor formatting
Merge pull request #102 from corvannoorloos/master

Add a space before colons. props @corvannoorloos
Merge pull request #101 from bryanstedman/master

Remove extra word "for" in README.md. props @bryanstedman
Fix tag list separator i18n in content-single.php