Skip older monotone versions for tests.

test-convert-mtn is known to work with 0.37 and 0.38, but fails with
0.31 (Debian etch). hghave now skips all versions up to 0.31.

tests/hghave

@@ -31,10 +31,11 b' def has_cvsps():'
     return matchoutput('cvsps -h -q 2>&1', r'cvsps version', True)
 
 def has_darcs():
-    return matchoutput('darcs', 'darcs version', True)
+    return matchoutput('darcs', r'darcs version', True)
 
 def has_mtn():
-    return matchoutput('mtn --version', 'monotone', True)
+    return matchoutput('mtn --version', r'monotone', True) and not matchoutput(
+        'mtn --version', r'monotone 0\.(\d|[12]\d|3[01])[^\d]', True)
 
 def has_eol_in_paths():
     try:
@@ -128,7 +129,7 b' checks = {'
     "git": (has_git, "git command line client"),
     "hotshot": (has_hotshot, "python hotshot module"),
     "lsprof": (has_lsprof, "python lsprof module"),
-    "mtn": (has_mtn, "monotone client"),
+    "mtn": (has_mtn, "monotone client (> 0.31)"),
     "svn": (has_svn, "subversion client and admin tools"),
     "svn-bindings": (has_svn_bindings, "subversion python bindings"),
     "symlink": (has_symlink, "symbolic links"),