Fixed androidify_substitutions for single % characters.

Test is: 
```
[progress]
	en = %@%% complete.
```

previous to this fix, this resulted in:

``<string name="progress">%1$s%2$ complete.</string>``

not it is (more)correctly producing:

``<string name="progress">%1$s% complete.</string>``

Some additional testing might be required to make sure this doesn't break anything else!



Also added a simple ``.gitignore``.