Paths with spaces do not work

[thomas-phillips-nz]

Upon inspecting the code and testing the build system, there are many many places in several scripts where if the current path (pwd) has spaces in it, the script will fail.
These should be cleaned up so we don't have to rely on the pwd having no spaces.

I have seen talk of changing the build script to python, but I have seen the dependency check script fail too. Looks like the whole build system needs to be modified to handle such paths.

[davesteele]

ff2d5ed may have helped.

[XECDesign]

Just had a look at this and even if I start fixing the bits which are broken in pi-gen, debootstrap still struggles - https://bugs.launchpad.net/ubuntu/+source/debootstrap/+bug/1716079

For example, just running sudo debootstrap buster "root fs" fails.

I tried running the above command on Buster on a pi and Ubuntu 19.10 on amd64, failing the same way both times.