Fix #1198, enable custom locale in template rendering, fixes links

reverts getpelican/pelican@ddcccfeaa9

If one used a locale that made use of unicode characters (like fr_FR.UTF-8)
the files on disk would be in correct locale while links would be to C.

Uses a SafeDatetime class that works with unicode format strigns
by using custom strftime to prevent ascii decoding errors with Python2.

Also added unicode decoding for the calendar module to fix period
archives.

samples/pelican_FR.conf.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+AUTHOR = 'Alexis Métaireau'
+SITENAME = "Alexis' log"
+SITEURL = 'http://blog.notmyidea.org'
+TIMEZONE = "Europe/Paris"
+
+# can be useful in development, but set to False when you're ready to publish
+RELATIVE_URLS = True
+
+GITHUB_URL = 'http://github.com/ametaireau/'
+DISQUS_SITENAME = "blog-notmyidea"
+PDF_GENERATOR = False
+REVERSE_CATEGORY_ORDER = True
+LOCALE = "fr_FR.UTF-8"
+DEFAULT_PAGINATION = 4
+DEFAULT_DATE = (2012, 3, 2, 14, 1, 1)
+
+ARTICLE_URL = 'posts/{date:%Y}/{date:%B}/{date:%d}/{slug}/'
+ARTICLE_SAVE_AS = ARTICLE_URL + 'index.html'
+
+FEED_ALL_RSS = 'feeds/all.rss.xml'
+CATEGORY_FEED_RSS = 'feeds/%s.rss.xml'
+
+LINKS = (('Biologeek', 'http://biologeek.org'),
+         ('Filyb', "http://filyb.info/"),
+         ('Libert-fr', "http://www.libert-fr.com"),
+         ('N1k0', "http://prendreuncafe.com/blog/"),
+         ('Tarek Ziadé', "http://ziade.org/blog"),
+         ('Zubin Mithra', "http://zubin71.wordpress.com/"),)
+
+SOCIAL = (('twitter', 'http://twitter.com/ametaireau'),
+          ('lastfm', 'http://lastfm.com/user/akounet'),
+          ('github', 'http://github.com/ametaireau'),)
+
+# global metadata to all the contents
+DEFAULT_METADATA = (('yeah', 'it is'),)
+
+# path-specific metadata
+EXTRA_PATH_METADATA = {
+    'extra/robots.txt': {'path': 'robots.txt'},
+    }
+
+# static paths will be copied without parsing their contents
+STATIC_PATHS = [
+    'pictures',
+    'extra/robots.txt',
+    ]
+
+# custom page generated with a jinja2 template
+TEMPLATE_PAGES = {'pages/jinja2_template.html': 'jinja2_template.html'}
+
+# code blocks with line numbers
+PYGMENTS_RST_OPTIONS = {'linenos': 'table'}
+
+# foobar will not be used, because it's not in caps. All configuration keys
+# have to be in caps
+foobar = "barbaz"