Update gitignore
Return properly from keyderiv
Factor out common error code
Mark rand/srand as static
Reorder
Cast before division
Handle multiple non-ASCII bytes in plaintext
Add test files and tools
Write out 8-bit clean result
Improve variable names
Use unsigned characters
Detect and accept UTF-8
Add an encoding/decryption check
Accept only valid UTF-8 streams
Improve variable names and factor out parameter
Factor out common CFLAGS
Show all compiler warnings
Add missing include
Comment-out currently-unused character maps
Make the compiler happy with our brace style