Infer a --repository argument from command arguments when reasonable. In particular: if invoked without -R from a CWD not inside a repo, having been passed one or more file paths as command arguments, where the nearest enclosing repo of all of those paths is the same, quietly infer a -R option for that repo. Otherwise abort with an error message as before.

--- a/tests/test-globalopts	Tue Feb 19 10:53:40 2008 -0800
+++ b/tests/test-globalopts	Fri Jan 25 04:11:32 2008 -0500
@@ -25,6 +25,13 @@
 hg -R a tip
 hg --repository b tip
 
+echo %% implicit -R
+hg ann a/a
+hg ann a/a a/a
+hg ann a/a b/b
+hg -R b ann a/a
+hg log
+
 echo %% abbrev of long option
 hg --repo c tip