Rewrite all /opt/app-root to $APP_ROOT variable

[Michal Josef Špaček]

s2i image has $APP_ROOT environment variable, but in code there are many hardcoded variables

[Petr Hracek]

This is already fixed by #236

[Michal Josef Špaček]

@phracek I don't think that is ok or that's working.

e.g.
https://github.com/sclorg/s2i-perl-container/blob/master/5.32/s2i/bin/assemble#L15
https://github.com/sclorg/s2i-perl-container/blob/master/5.32/s2i/bin/assemble#L101
Multiple hardcoded in https://github.com/sclorg/s2i-perl-container/blob/master/5.32/s2i/bin/run
Same https://github.com/sclorg/s2i-perl-container/blob/master/5.32/Dockerfile.fedora#L11

And most funny part:
https://github.com/sclorg/s2i-perl-container/blob/master/5.32/Dockerfile.fedora#L47

# Copy extra files to the image.
COPY ./root/ /

Which copies ./root/opt/app-root directly to /