Root of the issue is an (hidden!) parameter in ILMBase cmake options, that
is enabled by default, and force the generation of those ugly lib names
(Imf_2_2.so & co). Why why why enable such thing by default?
Anyway, it should be simpler to build again even on linuxes having the openexr -dev
package installed.
Also, cleaned up a bit things, now we can switch between repo and plain release archive
building from a single place for each lib, instead of commentting/uncommenting everything
each time (for libs where we have some git repo set up for some reason).
f4535c1a7a