* Update protolib to pick up new fixes
* CMake: restore SONAME_VERSION to 1
* CMake: generate pkg-config file
* CMake: set -fvisibility=hidden and POSITION_INDEPENDENT_CODE
Need to build everything with fPIC, and also hide symbols by default,
since public ones are explicitly marked as such.
* Revert public API incompatible changes
NormSetId and NormCountCompletedObjects were part of the public API in
released versions, so they cannot be just removed without breaking API/ABI
compatibility.
NormSendCommandTo is a private symbol, but was marked for export by
mistake.
* Add BUILD_STATIC_LIBS option to allow building both static and shared objects
CMake does not support this out of the box, so it has to be implemented
manually. It results in the libnorm build being repeated twice, as there's
no object sharing.
Luca Boccassi