add .gitignore
add .gitignore

add a .gitignore to reduce noise in git status etc.

leiyangyou/libvips,jcupitt/libvips,lovell/libvips,leiyangyou/libvips,leiyangyou/libvips,mcanthony/libvips,leiyangyou/libvips,mcanthony/libvips,jcupitt/libvips,lovell/libvips,wishabi/libvips,lovell/libvips,lovell/libvips,mcanthony/libvips,wishabi/libvips,jcupitt/libvips,wishabi/libvips,mcanthony/libvips,wishabi/libvips,jcupitt/libvips