Version 2.6.5 released

This version fixes a bug that caused small memory leaks. Specifically the wrap_*_without_ownership() functions in the vector and matrix classes would create an object that leaked four bytes when deleted. These functions are unusual, but are used, for example, with multimin. So four bytes would be lost each time one created an mutimin optimiser. There are a handful of other places where these can be called. The updates stop this leak.

Version 2.6.5 matches Gnu Scientific Library 2.6.5.