Clang ompilation fixes
This fixes two issues that raise errors with latest versions of clang.
In various files, static variables and functions were implicitly declared without a type specifier. Adding an "int" (the previous default) at all those places fixes this, done in the first commit.
Furthermore, one file used the function time() without "#include <time.h>" - fixed in the second commit.
See also: https://bugs.gentoo.org/884345