Fix overlapping memcpy
Merge pull request #34 from pperidont/fix_multipart

Fix overlapping memcpy
fix compiler warnings and GC depreceated
do not calculate the same size twice; declaring as const may enable optimizations
memcpy is a lot faster, yay
another one for memcpy
fix n bytes (it was luckily correct, but sizeof should be used)
fix indentation; use tabs