Basic Pijul support (ignoring VCS dir)

Pijul <https://pijul.org> is a decentralized version control system.

Ignorefile use .ignore which use the same as the Git-branded,
.gitignore file… so more advanced support could be added.

src/tup/pel_group.c

@@ -47,6 +47,8 @@ int pel_ignored(const char *path, int len)
 		return 1;
 	if(len == 4 && strncmp(path, ".svn", 4) == 0)
 		return 1;
+	if(len == 6 && strncmp(path, ".pijul", 6) == 0)
+		return 1;
 	if(len == 6 && strncmp(path, "_darcs", 6) == 0)
 		return 1;
 	if(len == 7 && strncmp(path, ".ccache", 7) == 0)

src/tup/server/fuse_fs.c

@@ -101,6 +101,8 @@ static int is_hidden(const char *path)
 		return 1;
 	if(strstr(path, "/.bzr") != NULL)
 		return 1;
+	if(strstr(path, "/.pijul") != NULL)
+		return 1;
 	if(strstr(path, "/_darcs") != NULL)
 		return 1;
 	if(is_ccache_path(path))