Clarify section 5 of -W and -S (Research and Development) and create an FAQ entry

Section 5 of -S and -W (see text below) grants permission to convey to a third party for R&D purposes, provided they are not able to use the Source or Products for their own use. This is an additional permission to those granted by the rest of the licence, and allows a licensee to use an external organisation for R&D without that organisation being granted rights for onward distribution etc. There is nothing stopping a licensee from treating an external R&D organisation as a normal third party, however. This sometimes causes confusion, that the fact that it's an additional permission should be referenced in any subsequent version, and the purpose of the section should be clarified in the FAQ.

5 Research and Development You may Convey Covered Source, modified Covered Source or Products to a legal entity carrying out development, testing or quality assurance work on Your behalf provided that the work is performed on terms which prevent the entity from both using the Source or Products for its own internal purposes and Conveying the Source or Products or any modifications to them to any person other than You. Any modifications made by the entity shall be deemed to be made by You pursuant to subsection 3.2.