Whatever that means
, Andy, hope you will explain everything when an update is up, as you always do. Thanks )
It means that Tragic Lantern is usually ahead of the 50D Unified build and any changes that happen in Tragic Lantern are not automatically included in the nightlies.
Developers work on their own synchronized copy of Magic Lantern code (called a 'fork'). Tragic Lantern is the name of one of these forks. Unified is the main fork.
Developers (like 1%) work on forks because they may want to add new features, make camera-specific changes or try out new stuff while keeping up-to-date with the constantly updated parent code.
When a developer has 'committed' changes (i.e. synchronized his local repository with his Bitbucket fork) they may choose to submit a 'pull request' which tells the developers of the main code that there is new/updated code
to be reviewed/considered for inclusion in Unified. After the code is reviewed it may or may not be merged (i.e. the new code may break rules, have bugs or need changes to syntax or other stuff and the dev will be asked to modify it). The process then repeats and only then (if the code is safe for inclusion in Unified) will those updates become part of 'Unified' and the automatic nightly builds.
It is done this way to keep the code cleaner and within the safe parameters set out by a1ex.
Tragic Lantern is fundamentally no different than Magic Lantern. It's shares the same code BUT Tragic Lantern does have extended features (for example: compare the TL raw module with the nightlies raw module) and other 'hacks' that may improve performance on the 50D/6D/EOS-M/600D. Regardless of the merge that happened recently, these features will not be in the Unified nightly builds. They are unique to Tragic Lantern.
Hope that helps you understand