Rename Selection Feature

[ghburman]

Allows the user to rename the selected file or folder by choosing "Rename" from the right-click context menu or by pressing F2.

• Supports single-entry selections only (notifies user of this when invoked on multi-entry selections)
• Similar to "Move to Trash", the user is notified that the database won't be aware of changes until the next update

I implemented this feature for my personal use, but think others might find it useful, too. I remain open to making changes/feedback.

Thank you to all who contribute to FSearch.