fixing typos and spelling + respect max characters of 80
fixing:  WARNING: Explicit markup ends without a blank line;
fixing:  WARNING: Title underline too short
fixing:  WARNING: Explicit markup ends without a blank line & WARNING: Enumerated list ends without a blank line
fixing: WARNING: Title underline too short
Merge branch 'stable6' into fixing-stable6

Conflicts:
	admin_manual/configuration/custom_mount_config_gui.rst
	admin_manual/maintenance/backup.rst
	admin_manual/maintenance/restore.rst
some more typos and line width fixes
some more typos and line width fixes
Merge branch 'stable6' into fixing-stable6

Conflicts:
	admin_manual/configuration/configuration_preview.rst
Merge pull request #194 from owncloud/fixing-stable6

fixing typos and spelling + respect max characters of 80