mcntp - hints for RSAEuro

• When compiling and linking with RSAEuro, it might be the case that some symbols (_NN_Cmp and such) are not found.
  Solution: there are two files rsa386.s and des386.s in which those symbols can be found as in

           .globl _NN_Cmp
  
  NN_Cmp:
  

  Here the first underscores must be removed as in

           .globl NN_Cmp
  
  NN_Cmp:
  

  For some systems it might also be the case that file.s must be renamed to file.S to be found by the assembler.
• Some compilers complain about unknown escape sequences in some files like e.g.:

  ../source/r_encode.c:72: warning: unknown escape sequence: `\' followed by char code 0xd
  

  This comes from the fact that lines atr÷are terminated by a ^M (Control-M) character. These must be eliminated by e.g. s/^M$// in vi