DOC: Cleanup PDP10 document

Development of functionality and features beyond Bob's editing role.

Official Released simh v3.9-0

imported from simhv39-0.zip and documents simhv39-0-doc_masters.zip

Import from simhv38-2-rc2.zip

Import from simhv38-2-rc1.zip

Import from simhv38-1.zip

Import from simhv38-0.zip

Import from simhv37-3.zip

Import from simhv37-2.zip

Import from simhv37-1.zip