sshpeer: add implementation of _calltwowaystream
This implements the call needed by bundle2. The error handling is a bit flaky
right now, but bundle2 error handling in general is still flaky anyway. Bundle2
is still disabled by default, I do not expect this to be a problem.
hg debuginstall
$ hg debuginstall
checking encoding (ascii)...
checking Python executable (*) (glob)
checking Python version (2.*) (glob)
checking Python lib (*lib*)... (glob)
checking installed modules (*mercurial)... (glob)
checking templates (*mercurial?templates)... (glob)
checking commit editor...
checking username...
no problems detected
hg debuginstall with no username
$ HGUSER= hg debuginstall
checking encoding (ascii)...
checking Python executable (*) (glob)
checking Python version (2.*) (glob)
checking Python lib (*lib*)... (glob)
checking installed modules (*mercurial)... (glob)
checking templates (*mercurial?templates)... (glob)
checking commit editor...
checking username...
no username supplied
(specify a username in your configuration file)
1 problems detected, please check your install!
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