[WIP] Suppress compiler warnings.

Disable a few Visual Studio warnings:

C4244: conversion from 'type1' to 'type2', possible loss of data
C4267: conversion from 'size_t' to 'type', possible loss of data

Considering the GCC/Clang counterpart '-Wconversion'
(https://gcc.gnu.org/wiki/NewWconversion) is not covered by '-Wall', it
seems to make more sense to disable these two warnings in Visual Studio,
rather than fixing these warnings with hundreds of static_cast<> in the
source code.

CMakeLists.txt

@@ -87,6 +87,8 @@ IF(MSVC)
 	IF (USE_MSVC_FAST_FLOATINGPOINT)
 		  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /fp:fast")
   ENDIF()
+
+	SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4244 /wd4267")
 ENDIF(MSVC)