Use absolute paths to specify run scripts and links.
Copy all available pngs to temp symbols directory.

Some symbol files use pngs, so need them available for the
conversion process.
Improve filesystem link handling.

Now
    .../BL02I/PS/9-1
    .../BL03I/PS/9-1
are linked to
   /<project_name>/BL02I/PS
   /<project_name>/BL03I/PS

Previously it was linked to
    /<project_name>/PS

The previous behaviour allowed ambiguities.

Similarly, project names are of the form BL02I_PS_9-1 instead of
PS_9-1.
Get real paths for PATH variable as well as EDMDATAFILES.