Track point to previous/next frame hangs

[Lawrence Wang]

When markers are already identified in certain frames and one tries to use the track point to previous/next frame functions to overwrite the existing markers, sometimes the cameras and graphs stop updating and only the frame number changes. Usually tracking forward or backward will fix this.

[Benjamin Knorlein]

fixes #40 : Removed some changes I added in the last version in hope to be more robust.

→ <<cset 1d14641b3983>>

[Benjamin Knorlein]

Hi Lawrence, I will release a new version end of this week. Can you test this issue with the new version next week and let me know if it still occurs? Thanks, Ben