Add long format specifiers "raw" and "hash"

Add new format specifiers to print the raw item representation or an
object's hash value.

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

src/event.c

@@ -40,6 +40,7 @@
 #include <time.h>
 
 #include "calcurse.h"
+#include "sha1.h"
 
 llist_t eventlist;
 
@@ -123,6 +124,16 @@ char *event_tostr(struct event *o)
 	return string_buf(&s);
 }
 
+char *event_hash(struct event *ev)
+{
+	char *raw = event_tostr(ev);
+	char *sha1 = mem_malloc(SHA1_DIGESTLEN * 2 + 1);
+	sha1_digest(raw, sha1);
+	mem_free(raw);
+
+	return sha1;
+}
+
 void event_write(struct event *o, FILE * f)
 {
 	char *str = event_tostr(o);