Remove indent workaround in man page RST sources

docutils 0.10 properly adds indentation to example blocks in man
pages, so we do not need to force an extra indentation level.  Get rid
of the workaround wherever we use it.

(I haven't assigned this a ticket or marked it for pullup, but perhaps I should.  We should also make sure that Tom's release machinery can easily use docutils 0.10+ to generate the man pages.)