Improve local datetime display

- Protect author's location privacy
- Reduce locale configuration parameters

_data/locales/en.yml

@@ -27,14 +27,6 @@ panel:
   trending_tags: Trending Tags
   toc: Contents
 
-#  The liquid date format › http://strftime.net/
-date_format:
-  tooltip: '%a, %b %e, %Y, %l:%M %p %z'
-  post:
-    long: '%b %e, %Y'
-    short: '%b %e'
-    archive_month: '%b'
-
 copyright:
   # Shown at the bottom of the post
   license:
@@ -62,11 +54,6 @@ post:
   written_by: By
   posted: Posted
   updated: Updated
-  timeago:
-    day: days ago
-    hour: hours ago
-    minute: minutes ago
-    just_now: just now
   words: words
   pageview_measure: views
   read_time: