It is defined multiple times through different translation
units.

Move parts from FileIO to GeoLib/IO and BaseLib/IO.

When building shared libraries -DBUILD_SHARED_LIBS=On must be passed to the
cmake invokation. Otherwise the default static linking applies.

This reduces the compile time, which is especially interesting for the debug
builds.

Christoph Lehmann authored 8 years ago and Dmitri Naumov committed 8 years ago

Returns boost::none in the case of error.