Builtin git-help.

This patch splits out git-help's functions to builtin-help.c and leaves
only functions used by other builtins in help.c.

First this removes git-help's functions from libgit which are not
interesting for other builtins, second this makes 'git help help' work
again.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

help.h

@@ -10,6 +10,12 @@ struct cmdnames {
 	} **names;
 };
 
+static inline void mput_char(char c, unsigned int num)
+{
+	while(num--)
+		putchar(c);
+}
+
 unsigned int load_command_list(const char *prefix,
 		struct cmdnames *main_cmds,
 		struct cmdnames *other_cmds);