Actually, I had to take a look at the documentation for gulp watch. It seems like generic blobs are  what gulp expects. Probably will take more time to do the less_for loop than just letting gulp process a generic glob.

Anyway, I went ahead and added in platform specific watches so you can do:
```
gulp watch_android
gulp watch_ios
gull watch_win
```
Otherwise, when building a specific platform, watch would automatically add in all three themes.