Changes since 8.10.5:
- don't seek on bad file descriptors [kleisauke]
- check for null memory sources [kleisauke]
- revise ppmload, fixing a couple of small bugs
- signal error on EOF in jpegload more reliably [bozaro]
- better error detection in spngload [randy408]
- fix includes of glib headers in C++ [lovell]
- fix build with more modern librsvg [lovell]
- fix a possible segv with very wide images [f1ac]
- fix issue thumbnailing RGBA images in linear mode [jjonesrs]
- revise profile handling in vipsthumbnail
- fix tiff deflate predictor setting [Adios]
- fix vector path for composite on i386 [kleisauke]