sshpeer: support not reading and forwarding stderr
The "doublepipe" primitive as used by sshpeer will automatically read
from stderr and forward output to the local ui.
This poses problems for deterministic testing because reads may not
be consistent. For example, the server may not be done sending all
output to stderr and the client will perform different numbers of
read operations or will read from stderr and stdout at different times.
To make tests deterministic, we'll need to disable the "doublepipe"
primitive and perform stderr I/O explicitly. We add an argument to the
sshpeer constructor to disable the use of the doublepipe.
Differential Revision: https://phab.mercurial-scm.org/D2467
{
// Enforcing
"eqeqeq" : true, // true: Require triple equals (===) for comparison
"forin" : true, // true: Require filtering for..in loops with obj.hasOwnProperty()
"freeze" : true, // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
"nonbsp" : true, // true: Prohibit "non-breaking whitespace" characters.
"undef" : true, // true: Require all non-global variables to be declared (prevents global leaks)
// Environments
"browser" : true // Web Browser (window, document, etc)
}