allow cproject to relate to sub/super directories

[petermr]

At present

ami-foo -p bar

only works if the caller's cwd is the parent directory of bar.
Explore whether it can be issued from:

• inside the bar tree

[petermr]

I believe this works. Assume a structure:

mystuff/
  cproject1/
    ctree1/
    ctree2/

then

cd mystuff
ls cproject1 // should show cproject1
ami-pdf -p cproject1  // should run
cd cproject1
ami-image -p .  // should run
ami-pixel -t ctree1 // should run
cd ctree2
ami-ocr -t . // should run ctree2

[petermr]

I will close if others can verify this.