Random collection of misc tools

* ccoincidences: Xor a file against itself at different offsets and count
                 coincidences. If the file is xored with a repeating
		 key, the length of the key should reveal itself.
* entropy: Calculate entropy (bits/byte, max 8) for a file
* invert: Invert all bytes in file (print result to stdout)
* isprime: Check if an integer is prime or not. Needs libgmp-dev.
           Edit Makefile if you don't have libgmp to skip this one.
* numunprintable: Count number of unprintable characters in file
* outbin: Read file containing hex characters, print binary representation
* reverse: Reverse all bytes in file (print result to stdout)
* subnet_calculator: Calculate ipv4 subnet range
* xorfiles: Xor contents of two files against each other