Bug#865565: libopenimageio-dev requires libilmbase-dev but lacks dependency

[Adrian Bunk]

Package: libopenimageio-dev
Version: 1.7.15~dfsg0-2
Severity: grave
Control: affects -1 src:opencolorio

https://buildd.debian.org/status/fetch.php?pkg=opencolorio&arch=mips&ver=1.0.9~dfsg0-11&stamp=1498157949&raw=0

...
In file included from /usr/include/OpenImageIO/fmath.h:64:0,
                 from /usr/include/OpenImageIO/hash.h:51,
                 from /usr/include/OpenImageIO/strutil.h:54,
                 from /usr/include/OpenImageIO/ustring.h:137,
                 from /usr/include/OpenImageIO/paramlist.h:52,
                 from /usr/include/OpenImageIO/imageio.h:61,
                 from /<<PKGBUILDDIR>>/src/apps/ociolutimage/main.cpp:33:
/usr/include/OpenImageIO/simd.h:56:30: fatal error: OpenEXR/ImathVec.h: No such 
file or directory
 #include <OpenEXR/ImathVec.h>
                              ^
...