Move platform-specific code of Hook to common file
Replace size_t and int with std:intptr_t in pointer arithmetic
Remove unnecessary size alignment code

mprotect() does not require the size argument to be page-aligned,
only address.
Refactor GetAmxPath code
Change name of the "gv" format to "dot"
Move common data to CallGraphWriter
Insert missing quotes around the script name
Remove redundant Write() method of CallGraph
Remove unused forward declaration and include
Fix members of StatisticsWriter not being initialized