[PATCH] Fix 64bit support

[Timo Sirainen <tss iki fi>]

I've always found Memprof to be the best tool when I've debugged issues related to why something is using up 
too much memory. Yesterday I was attempting to use Valgrind's Massif, but for some reason it was just giving 
completely wrong/useless information even after adjusting all the parameters. I couldn't find many other 
alternatives either, and nothing that gives as easy to use UI as Memprof.

I've now done a couple of fixes to make it work again for me - feel free to import to the memprof main git 
repository: https://github.com/sirainen/memprof

I also did a couple of other changes that made it more useful to me, including a separate "allocations" 
branch that replaces "Leaks" with listing all memory allocations instead (was too much effort to make it a 
separate tab).