Issue mozfr#530: host OpenSans font ourselves

* Don't provide fallbacks for old browsers, just use woff
* Cache them via .htaccess
* Put them in a local fonts folder

A quick check on my local instance gives good results on page load (/3)

web/.htaccess

@@ -13,11 +13,23 @@
 <IfModule mod_expires.c>
     ExpiresActive on
     ExpiresDefault                        "access plus 1 week"
+
     ExpiresByType application/json        "access plus 0 seconds"
-    ExpiresByType application/javascript  "access plus 1 year"
-    ExpiresByType application/font-woff   "access plus 1 month"
     ExpiresByType image/gif               "access plus 1 month"
     ExpiresByType image/jpeg              "access plus 1 month"
     ExpiresByType image/png               "access plus 1 month"
     ExpiresByType text/css                "access plus 1 year"
+    ExpiresByType application/font-woff   "access plus 1 year"
+    ExpiresByType application/javascript  "access plus 1 year"
+</IfModule>
+
+<IfModule mod_deflate.c>
+    # Compress all output labeled with one of the following MIME-types
+    # (for Apache versions below 2.3.7, you don't need to enable `mod_filter`
+    #  and can remove the `<IfModule mod_filter.c>` and `</IfModule>` lines
+    #  as `AddOutputFilterByType` is still in the core directives).
+    <IfModule mod_filter.c>
+        AddOutputFilterByType DEFLATE application/font-woff \
+                                      image/svg+xml
+    </IfModule>
 </IfModule>

web/style/transvision.css

@@ -1,33 +1,46 @@
 /* Fonts */
+/* Updated on www.mozilla.org 2015-06-17 */
 
 @font-face {
-    font-family: 'Open Sans';
+    font-family: 'Open Sans Light';
+    src: url(/fonts/OpenSans/OpenSans-Light-webfont.woff) format('woff');
+    font-weight: normal;
+    font-style: normal;
+}
+
+@font-face {
+    font-family: 'Open Sans Light';
+    src: url(/fonts/OpenSans/OpenSans-Semibold-webfont.woff) format('woff');
+    font-weight: bold;
     font-style: normal;
+}
+
+@font-face {
+    font-family: 'Open Sans Light';
+    src: url(/fonts/OpenSans/OpenSans-LightItalic-webfont.woff) format('woff');
     font-weight: normal;
-    src: url(https://www.mozilla.org/media/fonts/OpenSans-Regular-webfont.eot?#iefix) format('embedded-opentype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Regular-webfont.woff) format('woff'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Regular-webfont.ttf) format('truetype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Regular-webfont.svg#OpenSansRegular) format('svg');
+    font-style: italic;
 }
 
 @font-face {
     font-family: 'Open Sans';
+    src: url(/fonts/OpenSans/OpenSans-Regular-webfont.woff) format('woff');
+    font-weight: normal;
     font-style: normal;
-    font-weight: bold;
-    src: url(https://www.mozilla.org/media/fonts/OpenSans-Semibold-webfont.eot?#iefix) format('embedded-opentype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Semibold-webfont.woff) format('woff'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Semibold-webfont.ttf) format('truetype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Semibold-webfont.svg#OpenSansSemibold) format('svg');
 }
 
 @font-face {
-    font-family: 'Open Sans Light';
+    font-family: 'Open Sans';
+    src: url(/fonts/OpenSans/OpenSans-Bold-webfont.woff) format('woff');
+    font-weight: bold;
     font-style: normal;
+}
+
+@font-face {
+    font-family: 'Open Sans';
+    src: url(/fonts/OpenSans/OpenSans-Italic-webfont.woff) format('woff');
     font-weight: normal;
-    src: url(https://www.mozilla.org/media/fonts/OpenSans-Light-webfont.eot?#iefix) format('embedded-opentype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Light-webfont.woff) format('woff'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Light-webfont.ttf) format('truetype'),
-         url(https://www.mozilla.org/media/fonts/OpenSans-Light-webfont.svg#OpenSansLight) format('svg');
+    font-style: italic;
 }
 
 /* General structure */