fancyopts: Copy list arguments in command table before modifying.

Before this, executing
commands.dispatch(['log', '-r', '0'])
commands.dispatch(['log', '-r', 'tip'])
would look like:
hg log -r 0
hg log -r 0 -r tip

Reported by TK Soh, patch by Alexis S. L. Carvalho

mercurial/fancyopts.py

@@ -9,7 +9,10 b' def fancyopts(args, options, state):'
     for s, l, d, c in options:
         pl = l.replace('-', '_')
         map['-'+s] = map['--'+l] = pl
-        state[pl] = d
+        if isinstance(d, list):
+            state[pl] = d[:]
+        else:
+            state[pl] = d
         dt[pl] = type(d)
         if (d is not None and d is not True and d is not False and
             not callable(d)):