Merge branch 'bc/portable'

* bc/portable:
  Remove python 2.5'isms
  Makefile: add PYTHON_PATH to GIT-BUILD-OPTIONS
  t/aggregate-results: accomodate systems with small max argument list length
  t/t7006: ignore return status of shell's unset builtin
  t/t5150: remove space from sed script
  git-request-pull.sh: remove -e switch to shell interpreter which breaks ksh
  t/t5800: skip if python version is older than 2.5

diff --cc Makefile
Simple merge