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.

pelican/tests/output/custom_locale/theme/css/reset.css

@@ -0,0 +1,52 @@
+/*
+	Name: Reset Stylesheet
+	Description: Resets browser's default CSS
+	Author: Eric Meyer
+	Author URI: http://meyerweb.com/eric/tools/css/reset/
+*/
+
+/* v1.0 | 20080212 */
+html, body, div, span, applet, object, iframe,
+h1, h2, h3, h4, h5, h6, p, blockquote, pre,
+a, abbr, acronym, address, big, cite, code,
+del, dfn, em, font, img, ins, kbd, q, s, samp,
+small, strike, strong, sub, sup, tt, var,
+b, u, i, center,
+dl, dt, dd, ol, ul, li,
+fieldset, form, label, legend,
+table, caption, tbody, tfoot, thead, tr, th, td {
+	background: transparent;
+	border: 0;
+	font-size: 100%;
+	margin: 0;
+	outline: 0;
+	padding: 0;
+	vertical-align: baseline;
+}
+
+body {line-height: 1;}
+
+ol, ul {list-style: none;}
+
+blockquote, q {quotes: none;}
+
+blockquote:before, blockquote:after,
+q:before, q:after {
+	content: '';
+	content: none;
+}
+
+/* remember to define focus styles! */
+:focus {
+	outline: 0;
+}
+
+/* remember to highlight inserts somehow! */
+ins {text-decoration: none;}
+del {text-decoration: line-through;}
+
+/* tables still need 'cellspacing="0"' in the markup */
+table {
+	border-collapse: collapse;
+	border-spacing: 0;
+}