Various style cleanups
Moved stylesheets back to theme with data from DB; added header logo and body class to theme; NOTE: THIS REQUIRES A DB RELOAD TO GET THE THEME DATA
Added header title support; fixed style issue with accordion headers
Added notes about theme and dark/light switcher
Changed next release version from 1.4.2 to 1.5.0, meaning a change in XSD filenames which is important as the main reason for doing so is significant changes to the XSD files, especially the screen one
Merged from upstream, with changes for version change to 1.5 and theme changes and such