Fix merger connection bug

Fix inconsistent file prefix when using openephys recording format (o…

…pen-ephys#477)

Bump GUI version to v0.5.5.2

Fix splitter state restoration at start of acquisition

Update README

Bump GUI version to v0.5.5

Update README

Merge pull request open-ephys#443 from medengineer/fix-msg-center

Add missing return value to RecordNode::disable()

Bump GUI version to v0.5.4

Bump GUI version to v0.5.3.1