remote bot: manually set author/committer info to pusher
remote bot: manually set author/committer info to pusher

When the patches get committed locally, they run with the default git
settings (i.e. $env and ~/.gitconfig) rather than what was set up in
the repo checkout.  Manually force the author/committer fields to the
settings configured in the repo tree so that (1) the right credentials
are checked on the server and (2) the console can track things back to
the right developer.

BUG=chromium-os:27939
TEST=`cbuildbot --remote -g 19117 x86-generic-full` works and shows under 8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org
TEST=`./remote_try_unittest.py` passes

Change-Id: I01f3fdc271082755d9138f517f2e02f3ebbbb9d5
Reviewed-on: https://gerrit.chromium.org/gerrit/19171
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Commit-Ready: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>

bpsinc-native/src_third_party_chromite,zhang0137/chromite,chadversary/chromiumos.chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,coreos/chromite,coreos/chromite,coreos/chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite