CGI: Protect against bash(1) vulnerability.

bash(1) for some reason interprets environment variables with values
starting with "() {" as function definitions. These aliases are added
before any other processing.

In addition to the above, most versions of bash(1) released prior to
2014-09-24 had a bug, where any code after the function definition
was executed immediately.

This patch disables such functions by prefixing the value with a
single space.
Merge branch 'patches/bash-functions' into devel

* patches/bash-functions:
  CGI: Protect against bash(1) vulnerability.
Version bumped to 5.5.27 by buildsystem.
Scripting: Protect more places against Shellshock.

Roxen.build_roxen_env_vars() and Roxen.build_env_vars() now
attempt to protect against Shellshock.
Version bumped to 5.5.28 by buildsystem.
Merge branch 'patches/bash-functions' into devel

* patches/bash-functions:
  Scripting: Protect more places against Shellshock.