Separate declaration and definition of inline functions; add an ALWAYS_INLINE...

Separate declaration and definition of inline functions; add an ALWAYS_INLINE define in types.h for GCC-based compilers to make sure to inline even in non-optimized builds, which is required.

git-svn-id: http://svn.net-core.org/repos/t-engine4@797 51575b47-30f0-44d4-a5cc-537603b46e54