Set FOREMAN_PROCESS_NAME env var for spawned procs

This way, processes can identify themselves to metrics logging systems.
added support for directories with single quotes. fixes #315
fixes #315
third time is the charm. :)
modified to use shellescape instead of gsub
rough draft for systemd export support

http://0pointer.de/blog/projects/systemd.html

This adds support for exporting systemd targets and services.  The
structure is based on the existing upstart support.

Quality is draft and expected to refine in the coming weeks.

One Foremanism that is not respected by these export templates is the
usual log output location, instead stdout and stderr go to syslog.
better default for things which intentionally daemonize child processes, the default KillMode is control-group which survives daemonization
fix spec after d4ab495
Revert "Merge pull request #292 from andrewsmedina/master"

Does not pass tests

This reverts commit 17a8a316b886ca61e2b7d6b841fd6acdcd5c38d6, reversing
changes made to 9e1d590734d826d5c0756f78963271f74edf0852.
fix up tests
fix dotenv dependency
0.63.0
changelog
Change FOREMAN_PROCESS_NAME to just PS
Add unit test for PS env var
Fix typo in manual page.
updated systemd export spec after rebasing included 5ef8bbdb
Merge pull request #294 from bfulton/master

add systemd export
Ruby 1.8 doesn't have the concept of string encodings. Compare to the string as is.
Use pipe factory method to handle 1.8 incompatible signature for IO.pipe.