Move javaUTF8Decode function to util.js
Nativize DataInputStream::readUTF. Fixes #368
Remove DataInput from custom/
Merge branch 'master' of https://github.com/andreasgal/j2me.js into datainputstream_readutf
Merge pull request #583 from marco-c/datainputstream_readutf

Implement DataInputStream::readUTF in JS