mq: fix qimport --name --existing --force on win32

os.rename() does not overwrite existing targets on Windows.

hgext/mq.py

@@ -1699,7 +1699,7 b' class queue(object):'
 
                     self.ui.write(_('renaming %s to %s\n')
                                         % (filename, patchname))
-                    os.rename(originpath, self.join(patchname))
+                    util.rename(originpath, self.join(patchname))
                 else:
                     patchname = filename
 

tests/test-mq-qimport

@@ -118,3 +118,10 b' hg qdel -k 2.diff'
 echo % qimport -e --name newname oldexisitingpatch
 hg qimport -e --name this-name-is-better 2.diff
 hg qser
+echo % qimport -e --name without --force
+cp .hg/patches/this-name-is-better .hg/patches/3.diff
+hg qimport -e --name this-name-is-better 3.diff
+hg qser
+echo % qimport -e --name with --force
+hg qimport --force -e --name this-name-is-better 3.diff
+hg qser

tests/test-mq-qimport.out

@@ -61,3 +61,12 b' renaming 2.diff to this-name-is-better'
 adding this-name-is-better to series file
 this-name-is-better
 url.diff
+% qimport -e --name without --force
+abort: patch "this-name-is-better" already exists
+this-name-is-better
+url.diff
+% qimport -e --name with --force
+renaming 3.diff to this-name-is-better
+adding this-name-is-better to series file
+this-name-is-better
+url.diff