bump to 4.7.4 for sage 6.2

Package-Manager: portage-2.2.8-r1
Getting ready for 6.2.beta3 and fixes to build docs

Package-Manager: portage-2.2.8-r1
fixing sage-doc-9999-r1 with Steve's help.

Package-Manager: portage-2.2.8-r1
Bump libgap to match gap

Package-Manager: portage-2.2.8-r1
Drop some keywords that are no longer necessary.