Gitignore parsing iterates through all directories unnecessarily

[another-rex]

The git ignore parsing logic always iterates down through all directories, even ignored directories.

This causes scans that don't use the -r flag to take a surprisingly long time to complete, and also causes large, directory structures that have been ignored to take a long time to scan, since those directories are walked through to find ignore files.

[robotdana]

i can take a look at this

[robramsaynz]

Can you assign this to me please @another-rex