Update user_manual/calendars.rst

Updated URLs to the correct ones for OC 4.0/4.5
New calendar images (created with 4.5.5)
Add link which is not fully shown in pic
Update user_manual/calendars.rst

Updated URLs to the correct ones for OC 4.0/4.5
New calendar images (created with 4.5.5)
Add link which is not fully shown in pic
Corrects dependency list (contained invalid pkgs)
Adds installation instructions for debian/ubuntu

For ubuntu/debian the instructions on how to install the server from repositories was missing.
owncloud -> ownCloud
Merge pull request #26 from RandolfCarter/LinuxInstall45

Corrects 4.5 Manual installation instructions & adds for Ubuntu/Debian
added appframework changes
added change in controller api
updated tutorial
updated docs to fit appframework changes
Add owncloud.com theme
Merge remote branch 'origin/stable45'

Conflicts:
	admin_manual/installation_source.rst
update theme
Merge remote branch 'origin/stable45'
Replace redundant unit testing chapter

Fixes #27.
adjust chapter name