I used to have DNS like version codes (YYYYmmmddXX format) for my apps builds, and I can't go back in older apps because Google Play wont allow me to upload inferior version codes, so I thing we should to use BigInteger instead of Integer.parseInt
This closes#298
Wasn't being used anyways, and it still referenced android-19
This also switches to using a Properties object rather than a RegEx
for parsing project.properties