Some fixes and many more notes and clarifications.

Moved SSL remark from nginx to general webserver section and elaborated more on the reasons why to use it.
Added sudo in various places where root permissions are required (but where there was no explicit mention of it).
Moved part of WebDAV remark from modules to be installed to webserver configuration, added note about disabling authentication.
Add SSL configuration for apache
And more

correct formatting, complete apache configuration

various improvements

formatting, reduce notes, more bullet lists, more detailed SSL note.

more formatting and other fixes

various fixes

add hint that mysql&apache are used in example

fix formatting for apache version script

Conflicts:
	admin_manual/installation/installation_source.rst