chg: do not redirect stdout to /dev/null Redirecting stdout to /dev/null has unwanted side effects, namely ui.write will stop working. This patch removes the redirection code and helps chg to pass test-bad-extension.t.

pager: skip uisetup if chg is detected chg has its own pager implementation that it wants to skip pager's uisetup. It is currently done by redirecting stdout to /dev/null, which has unintended side effects. This patch makes pager aware of chg and skip uisetup directly from pager. We may want to merge chg and pager's pager implementation to make this unnecessary in the future.