Added PION_COMMON_API declaration to struct pion::PionLogger.
Added PION_COMMON_API declaration to struct pion::PionLogger.

acmorrow/pion-core,acmorrow/pion-core,acmorrow/pion-core,acmorrow/pion-core,acmorrow/pion-core,acmorrow/pion-core,acmorrow/pion-core