authentication_handler implementaion

Authentication handler allows to delegate http authentication to external
program. It introduces one new configuration variable: authentication_handler.
Note that this commit does not affect uzbl behaviour unless this variable is
set.  Also updated README documentation, default config and added example
authentication script.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/callbacks.h b/src/callbacks.h
index 3f318f2..7fe5c19 100644
--- a/src/callbacks.h
+++ b/src/callbacks.h
@@ -13,6 +13,9 @@ void
 set_proxy_url();
 
 void
+set_authentication_handler();
+
+void
 set_icon();
 
 void