Remove utf8.hh

Unused -- was just a convenience header for utfcpp.
diff --git a/src/ext/utf8.h b/src/ext/utf8.h
deleted file mode 100644
index 285f77b..0000000
--- a/src/ext/utf8.h
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2006 Nemanja Trifunovic
-
-/*
-Permission is hereby granted, free of charge, to any person or organization
-obtaining a copy of the software and accompanying documentation covered by
-this license (the "Software") to use, reproduce, display, distribute,
-execute, and transmit the Software, and to prepare derivative works of the
-Software, and to permit third-parties to whom the Software is furnished to
-do so, all subject to the following:
-
-The copyright notices in the Software and this entire statement, including
-the above license grant, this restriction and the following disclaimer,
-must be included in all copies of the Software, in whole or in part, and
-all derivative works of the Software, unless such copies or derivative
-works are solely in the form of machine-executable object code generated by
-a source language processor.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
-SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
-FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
-ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.
-*/
-
-
-#ifndef UTF8_FOR_CPP_2675DCD0_9480_4c0c_B92A_CC14C027B731
-#define UTF8_FOR_CPP_2675DCD0_9480_4c0c_B92A_CC14C027B731
-
-#include "../config.hh"
-
-#if USE_EXCEPTIONS
-#include "utf8/checked.h"
-#endif
-#include "utf8/unchecked.h"
-
-#endif // header guard