#8695: some minor improvements to the main testing document  - reformatting  - added `.. envvar ::`  - removed some dead links and obsolete win32 info  - briefly mention `coverage`
#8695: some minor improvements to the main testing document
 - reformatting
 - added `.. envvar ::`
 - removed some dead links and obsolete win32 info
 - briefly mention `coverage`


git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@10283 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac