Restoer Ability to Set Header Height

[Jeremy Hopkins]

There used to be a setting pageheaderheight which allowed admins to set the height of the main header area containing the logo.

There are still references to this in lang and lib settings but the admin setting itself has been removed.

We need to put this setting back so we can reduce the size of the header.

[Manoj Solanki]

Fix #741. Also removed default width and height from logocontainer class in css styling

→ <<cset c26300470bd9>>