Add build tool version comment
Add build tool version comment

This adds a list of tool releases with their respective release
dates and why they are important for libgphoto2 (libexif
requirements, notable bug fixes and features).

gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2