run-tests.py: don't let hg run interactively in debug mode

In normal test mode stdin is closed and hg is thus not interactive. In --debug
mode stdin is inherited from the running console and to the tests, and hg could
thus wait in prompts when running on Windows.

See http://selenic.com/pipermail/mercurial-devel/2013-January/047548.html .

Instead set ui.interactive=False to make Mercurial non-interactive. Other
commands might still work differently in the --debug environment.

This should solve the problem with hg waiting for input but still make it
possible to add --debugger to hg in a test and run run-tests.py with --debug.

tests/run-tests.py

@@ -874,6 +874,7 b' def runone(options, test):'
     hgrc = open(HGRCPATH, 'w+')
     hgrc.write('[ui]\n')
     hgrc.write('slash = True\n')
+    hgrc.write('interactive = False\n')
     hgrc.write('[defaults]\n')
     hgrc.write('backout = -d "0 0"\n')
     hgrc.write('commit = -d "0 0"\n')

tests/test-commandserver.py.out

@@ -75,6 +75,7 b' defaults.backout=-d "0 0"'
 defaults.commit=-d "0 0"
 defaults.tag=-d "0 0"
 ui.slash=True
+ui.interactive=False
 ui.foo=bar
  runcommand init foo
  runcommand -R foo showconfig ui defaults
@@ -82,6 +83,7 b' defaults.backout=-d "0 0"'
 defaults.commit=-d "0 0"
 defaults.tag=-d "0 0"
 ui.slash=True
+ui.interactive=False
 
 testing hookoutput: