log, vendor: vendor in log15 inline into our codebase

log/term/terminal_solaris.go

@@ -0,0 +1,9 @@
+package term
+
+import "golang.org/x/sys/unix"
+
+// IsTty returns true if the given file descriptor is a terminal.
+func IsTty(fd uintptr) bool {
+	_, err := unix.IoctlGetTermios(int(fd), unix.TCGETA)
+	return err == nil
+}