Allow environmental variables to be passed to the bkd using 'bk push -EVAR' so that they can be used for user triggers.
Allow environmental variables to be passed to the bkd using
'bk push -EVAR' so that they can be used for user triggers.

bk: 4215f591SLS__MJMOR2HmK1uZvuj0g
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper