give worst-case 'merge' merge-tool lowest priority
Another tool had -10 already. Since 'merge' is clearly a worst-case
tool (internal), lowering to -100 ensures there's plenty of room for
slightly better cases.
--- a/contrib/mergetools.hgrc Wed Apr 21 11:57:45 2010 -0500
+++ b/contrib/mergetools.hgrc Wed Apr 21 12:02:51 2010 -0500
@@ -13,7 +13,7 @@
gvimdiff.priority=-9
merge.checkconflicts=True
-merge.priority=-10
+merge.priority=-100
gpyfm.gui=True