cmdutil: replace sys.maxint with None as default value in loglimit
Semantically, it is better to use None over any other value when there is
"no value". Using maxint in this context is quite hackish, and is not forward
compatible.
% init
adding a
% fold in the middle of the queue
popping p3
popping p2
now at: p1
--- a/a
+++ b/a
@@ -1,1 +1,2 @@
a
+a
p1
p3
--- a/a
+++ b/a
@@ -1,1 +1,3 @@
a
+a
+b
% fold with local changes
abort: local changes found, refresh first
--- a/a
+++ b/a
@@ -1,1 +1,3 @@
a
+a
+b