Megalexxx: Uncompression for compressed 1st_read and other removers

[Megalexxx]

About RNC :
_ RNC is bugged : try to launch it, it will say syntax is incorrect. I found out why, but still have to find some time to take a look at the coding
_ DeRNC seems to look for "RNC" string in the files it has to decompress. I didn't find it in any 1st_read.bin.

So the algorithm might be OK, but it needs some changes to work on those compressed 1st_read.bin...