i18n-pt_BR: synchronized with 2664f536a97e

util: allow to specify buffer size in popen4 We will need unbuffered IO to restore real time output with ssh peer. Changeset ec171737aaf1 seems to indicate playing with this value could be dangerous, but does not indicate why.

sshpeer: extract the forward output logic We are about to make a more aggressive use of this when reading and writing on the other pipes. We it needs to be reusable.