Create Java6 bytecode for transdroid.jar

Android will only be able to create Dalvik bytecode if the input Java
bytecode is in Java6 format. Otherwise we get a bunch of
NoClassDefFoundError Exceptions along with "Could not find class X",
"Unable to resolve static method Y" and such errors for code in
transdroid.jar.
Create build directory for transdroid.jar

if it does not exists already.
Merge pull request #88 from Flowdalic/60

Create Java6 bytecode for transdroid.jar