COMP: std::abs integral overloads not always provided

Some older C++ compilers do not provide integral overloads for
std::abs.

For example, on Visual Studio 9, vcl_abs works for long long while
std::abs does not provide a long long overload.

To accomodate this compiler, the patch uses vcl_abs.

Change-Id: I6749e452699b1ca999eb3c6464fb17605ebaa682
Merge topic 'AbsOverload'

e09e598a COMP: std::abs integral overloads not always provided