No fixed bash executable location.

Because there are system that don't have bash in `/bin/bash` but in
`/usr/bin/bash` or even `/usr/local/bin/bash`. The tool `/usr/bin/env`
is used to determine the location of `bash`.
Closes #649: java_cmd should not be declared readonly since the command-line parsing overwrites it
Merge pull request #779 from sethyates/master

Closes #649: java_cmd should not be declared readonly since the command-line parsing overwrites it
Adding quotation marks around 'cd' commands
Merge pull request #707 from makubi/activator-bash-script-path-fix

Adding quotation marks around 'cd' commands
Merge pull request #589 from wegtam/fix-bash-location

No fixed bash executable location.