Squashed multiple commits

1. Added -Wno-unused-parameter
2. Make sure std::size_t is defined when it's being used
3. stlport: Fix incompatibility with clang++ (used by llvm)
   in ISO C++11 mode.
4. Fix strict aliasing violations
5. Force building PIC code (Required for gcc 4.7)

Credits : Bernhard Rosenkraenzer

Signed-off-by: dragon <dragon7780@hotmail.nl>