Accept newer magic bytes for dex files

Currently if a ICS+ extended opcode file was passed to radare2 it
would fail to parse it properly. This checks for the two conditions
'dex\n035\0' and 'dex\n036\0' - and will also just attempt to parse
it if the magic bytes 'dex\n' are available. This should suffice since
the last four bytes are the versioning bytes.