Added a "child" attr to createTag(...) and changed an if-else chain to a switch.
Added a dropdown that sets the current project.

 - Added a function to render a select tag with the projects in it.
 - Said rendered select is added to the page header.
 - Selecting something changes the current pid.
 - Time entries now use the current pid (!!).
Added storage and loading of project mappings and made the dropdown look good.