OSPL-2752 OSPL_V6_3-01-branch Updated doxygen git tag

(cherry picked from commit 2053f4429d109acfd279932dec689b8d67739ce8)

Conflicts:
	etc/docs_git_tag
OSPL-2752 Fix make clean. Also fix some ISO C++ errors.

(cherry picked from commit d88d28f81bd4080702487c8e6703c81bf45aa726)