Also adds better documentation and removes the one-off reimplementation
of the function in pica.h.

It is of very limited practical utility currently, and will soon be
impossible to support due to more accurate memory map emulation.

Kernel: Process class and ExHeader caps parsing

This has been obsoleted by the field in Process.

dyncom: Remove an unnecessary variable in the interpreter

Remove unnecessary dyncom header files

All this was doing was needlessly aliasing a variable.

Remove unused hash and mem_arena from common

string_util: Get rid of UriDecode/UriEncode

Profiler: Fix off-by-one error when computing average.

Common: Add proper macros to test for architecture pointer size

It is superfluous for Citra. (It's only really necessary if you're doing
JIT. We were using it but not taking any advantage from it.) This should
make 32-bit builds work again.

Currently unused and the code quality is pretty questionable.

The old system of just defining macros available in some other platform
was susceptible to silently using the wrong code if you forgot to
include a particular header. This fixes a crash on non-Windows platforms
introduced by e1fbac3c.

More cleanups