Add PEAR bin dir to the PATH variable

Trello card: https://trello.com/c/J5McYMNq (origin_runtime_169)
Modify doc to account for per-distro proxy behavior
Merge pull request #3412 from nhr/doc_fix

Modify doc to account for per-distro proxy behavior
Merge pull request #2984 from VojtechVitek/pear_path

Merged by openshift-bot