packager: support wildcards in yaml file

Adding wildcards will make constructing yaml files less tedious.

Currently, you have to list every file:

```
files:
# These are some examples as comments, please modify, add, delete as necessary:
OFL.txt: OFL.txt
DESCRIPTION.en_us.html: DESCRIPTION.en_us.html
FONTLOG.txt: FONTLOG.txt
fonts/ttf/KumbhSans-Regular.ttf: KumbhSans-Regular.ttf
fonts/ttf/KumbhSans-Bold.ttf: KumbhSans-Bold.ttf
fonts/ttf/KumbhSans-Light.ttf: KumbhSans-Light.ttf
```

If we have wildcards:

```
files:
# These are some examples as comments, please modify, add, delete as necessary:
OFL.txt: OFL.txt
DESCRIPTION.en_us.html: DESCRIPTION.en_us.html
FONTLOG.txt: FONTLOG.txt
fonts/ttf/*.ttf: *.ttf
```