Update Fira Sans to version 4.202

From https://github.com/mozilla/Fira

Author: Manishearth

src/librustdoc/html/static/FiraSans-LICENSE.txt

@@ -1,10 +1,5 @@
-Copyright (c) 2014, Mozilla Foundation https://mozilla.org/
-with Reserved Font Name Fira Sans.
-
-Copyright (c) 2014, Mozilla Foundation https://mozilla.org/
-with Reserved Font Name Fira Mono.
-
-Copyright (c) 2014, Telefonica S.A.
+Digitized data copyright (c) 2012-2015, The Mozilla Foundation and Telefonica S.A.
+with Reserved Font Name < Fira >, 
 
 This Font Software is licensed under the SIL Open Font License, Version 1.1.
 This license is copied below, and is also available with a FAQ at:
@@ -24,7 +19,7 @@ with others.
 
 The OFL allows the licensed fonts to be used, studied, modified and
 redistributed freely as long as they are not sold by themselves. The
-fonts, including any derivative works, can be bundled, embedded,
+fonts, including any derivative works, can be bundled, embedded, 
 redistributed and/or sold with any software provided that any reserved
 names are not used by derivative works. The fonts and derivatives,
 however, cannot be released under any other type of license. The