Separate Eina exporting/importing symbols from other libraries. Other
libraries will also be separated.
This makes it easier to rationalize and fix problems when
importing/exporting symbols in platforms such as Windows which
separates importing from exporting.
Also, I've made DLL standard. If built as static needs to define
EINA_STATIC. This way, users of the shared library will not need
to define anything to use it.
Depends on D11995