Removed improper casts.
Thanks to Joerg Bruehe for the fix.


include/my_global.h:
  Build bug on 64-Bit platforms.
  Removed improper casts.
  Changed to uniform writing style.
  Appended 'L' to 32-Bit constants which doesn't hurt on 32-Bit,
  but can be important for some 64-Bit compilers.