Add project description to project and tasks

A project and task description should be added to translate5 as follows:

• Naming: EN: "Project description"; DE "Projektbeschreibung"
• Add project wizard: Text area on first screen where user can input up 500 characters
• Project grid and task grid: New text column behnd order number; Text is automatically truncated where the column width ends at the moment (if this works easily). A tool tip shows the entire content and the usual info icon points to this
• Editor: See screenshot.