improve wsgi documentation

[Reimar Bauer]

setup of samples for a mod_wsgi implementation have to become updated

vhost configuration

also a big hint for setting the PROJ_LIB env var has to be added

and hint about setting up wsgi.load and wsgi.conf based on the mod_wsgi version

[Reimar Bauer]

Issue #412 was marked as a duplicate of this issue.

[Reimar Bauer]

improved documentation for setting up apache2 wsgi instances, fixes #409

→ <<cset d45469ebd674>>

[Reimar Bauer]

Merged in ReimarBauer/mss/docs (pull request #644)

improved documentation for setting up apache2 wsgi instances, fixes #409

→ <<cset 02819c0fb57a>>