Get PID from jobs command

To fix 9dbcdd5 problem.
fix Job ID to satisfy POSIX.1-2008

http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_204
Add original checkbashisms.pl #30

http://anonscm.debian.org/cgit/collab-maint/devscripts.git/commit/scripts/checkbashisms.pl?id=68e6970dd7a536a736270075a655d30633ca9022
$ wget http://anonscm.debian.org/cgit/collab-maint/devscripts.git/plain/scripts/checkbashisms.pl
Switch checkbashisms rule to accept jobs command #30

POSIX2_UPE must be supported to execute shoreman.
http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap02.html#tag_02_01_03_02
Execute fixed checkbashisms.pl #30
Revert "Use sh(1) in Makefile for consistency"

This reverts commit d29f46661bb119d7925574b3097da62d8eb7509c.
Merge branch 'master' into get-jobs-pid
Switch back to Bash #30

In Dash (Debian default /bin/sh), jobs command didn't work properly.
Merge pull request #30 from koseki/get-jobs-pid

Get PID from jobs command
Update README
Make sure failure in the middle of a pipe is caught

Normally, the success or failure of a pipeline is decided by the last command.
Cleanup and make code more consistent

- Use bash's extended test command - [[ ... ]]
- Quote some unquoted $ signs
- Use local instead of global in load_env_file