Enhancement request: SyncTeX support

[kbauer]

It would be desirable for appendix contents to have SyncTeX support, and for \newtheoremrep environments to have SyncTeX inverse search to point to the correct line rather than the final \end tag.

I spent some (too much time) trying to find a solution myself, so this might not actually be feasible. At least, it would require a significant rewrite of core mechanisms.