- removes redundant `if (df::global::ui)` checks; and tested to ensure no segfaults cropped up like in the past times I've removed these
- removes useless `if (pause_lock)` pause lock is set when plugin initializes, even if pause lock was left null (since we technically don't need it, and that was the point of the null check) it still would be a useless check (actually an impediment preventing functionality)
- removes disabled interpose code
- removes lua linkage
- updates doc
extra:
- surrounds user input for tick frequency with `std::abs()` not that we would have ended up with a negative value, but it was probably a typo and this is easier than printing an error or letting it underflow past max int (on most systems)