Merge pull request #583 from libavg/features/windows_firebirds

Merged features/windows firebirds
Revert firebirds win build merge.

This reverts commit 87231e84ecfa0408da9b309d2029a16f53f7b76e, reversing
changes made to 5dabd0c486bc58d73fb1e7d5de44433d2995225f.