Removed VS6 and VS7 workarounds

Assume that if _MSC_VER is defined that it is >= 1310
(ie VS7.1).

This improves the readability of the code, and slightly
improved code coverage.

Change-Id: Iffc601f4cff53c4e267835e39b2b17a3adf74494
Merge topic 'old_MSC_VER' into master

de8eae2b Removed VS6 and VS7 workarounds