Faster file list

this uses one combined regexp for pathFilter patterns, which makes nak much faster

after second run `time bin/nak -l .` in nak directory becomes

```
real    0m0.138s
user    0m0.104s
sys     0m0.044s
```
from

```
real    0m0.737s
user    0m0.676s
sys     0m0.072s
```