MIME: use "application/javascript" for .js files.

Though there are several MIME types commonly used for JavaScript nowadays,
the most common being "text/javascript", "application/javascript", and
currently used by nginx "application/x-javascript", RFC 4329 prefers
"application/javascript".

The "charset_types" directive's default value was adjusted accordingly.
diff --git a/conf/mime.types b/conf/mime.types
index 8a218b2..2a4bd73 100644
--- a/conf/mime.types
+++ b/conf/mime.types
@@ -5,7 +5,7 @@
     text/xml                              xml;
     image/gif                             gif;
     image/jpeg                            jpeg jpg;
-    application/x-javascript              js;
+    application/javascript                js;
     application/atom+xml                  atom;
     application/rss+xml                   rss;
 
diff --git a/src/http/modules/ngx_http_charset_filter_module.c b/src/http/modules/ngx_http_charset_filter_module.c
index 27a00d0..c9b7e9e 100644
--- a/src/http/modules/ngx_http_charset_filter_module.c
+++ b/src/http/modules/ngx_http_charset_filter_module.c
@@ -128,7 +128,7 @@
     ngx_string("text/xml"),
     ngx_string("text/plain"),
     ngx_string("text/vnd.wap.wml"),
-    ngx_string("application/x-javascript"),
+    ngx_string("application/javascript"),
     ngx_string("application/rss+xml"),
     ngx_null_string
 };