Add support for .f file lists

[DeeeeLAN]

Hello,

all of our projects are bigger and so we manage the different sets of files with .f file lists to make sure we compile the right files when needed. The current configuration file appears to only support direct file paths to source code, not to file lists. It would be great to scan and parse the file lists for the source code paths so there isn't any duplication of paths that require twice as much maintenance if something changes.

[suoto]

HDL Checker has means to work out dependencies and compilation sequence, so all you should need is to let it know where the files are; there's support for config files hierarchy (so a component might have its own config file and the top level project only needs to include that), wildcards and relative paths, which solve most scenarios.

For cases where this is not enough, what I've done in the past is write a config generator script -- many languages have JSON libraries and that was one of the reasons I chose it.

The problem of supporting tool specific files is that vendors don't provide an open API to read and interpret them, so supporting them can be very time consuming because it's essentially chasing a moving target and I've steered away from.