The only thing in helpers.py that needed vars.py was the log stuff.

So put it in its own file.  Now it's safer to import and use helpers even if
you can't safely touch vars.

log.py

@@ -0,0 +1,49 @@
+import sys, os
+import vars
+
+def log_(s):
+    sys.stdout.flush()
+    if vars.DEBUG_PIDS:
+        sys.stderr.write('%d %s' % (os.getpid(), s))
+    else:
+        sys.stderr.write(s)
+    sys.stderr.flush()
+
+
+def _clog(s):
+    log_('\x1b[32mredo  %s\x1b[1m%s\x1b[m' % (vars.DEPTH, s))
+def _bwlog(s):
+    log_('redo  %s%s' % (vars.DEPTH, s))
+
+def _cerr(s):
+    log_('\x1b[31mredo: %s\x1b[1m%s\x1b[m' % (vars.DEPTH, s))
+def _bwerr(s):
+    log_('redo: %s%s' % (vars.DEPTH, s))
+
+def _cwarn(s):
+    log_('\x1b[33mredo: %s\x1b[1m%s\x1b[m' % (vars.DEPTH, s))
+def _bwwarn(s):
+    log_('redo: %s%s' % (vars.DEPTH, s))
+
+
+if os.isatty(2):
+    log = _clog
+    err = _cerr
+    warn = _cwarn
+else:
+    log = _bwlog
+    err = _bwerr
+    warn = _bwwarn
+
+
+def debug(s):
+    if vars.DEBUG >= 1:
+        log_('redo: %s%s' % (vars.DEPTH, s))
+def debug2(s):
+    if vars.DEBUG >= 2:
+        log_('redo: %s%s' % (vars.DEPTH, s))
+def debug3(s):
+    if vars.DEBUG >= 3:
+        log_('redo: %s%s' % (vars.DEPTH, s))
+
+