Import cgit prototype from git tree

This enables basic cgit functionality, using libgit.a and xdiff/lib.a from
git + a custom "git.h" + openssl for sha1 routines.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.h

@@ -0,0 +1,21 @@
+#ifndef CGIT_H
+#define CGIT_H
+
+#include "git.h"
+#include <openssl/sha.h>
+
+extern char *fmt(const char *format,...);
+
+extern void html(const char *txt);
+extern void htmlf(const char *format,...);
+extern void html_txt(char *txt);
+extern void html_attr(char *txt);
+
+extern void html_link_open(char *url, char *title, char *class);
+extern void html_link_close(void);
+
+typedef void (*configfn)(const char *name, const char *value);
+
+extern int cgit_read_config(const char *filename, configfn fn);
+
+#endif /* CGIT_H */