* refactor: add a Mediator class to decouple tr_session and tr_port_forwarding
* refactor: add tr_port_forwarding::Mediator::privatePeerPort()
* refactor: add tr_port_forwarding::Mediator::onPortForwarded()
* chore: avoid unnecessary include of timer.h in other headers
* refactor: use a uniform timerMaker() API in mediators
This way all the qualifiers (`const`, `volatile`, `mutable`) are grouped
together, e.g. `T const* const x` vs. `const T* const x`. Also helps reading
types right-to-left, e.g. "constant pointer to constant T" vs. "constant
pointer to T which is constant".
There're places where manual intervention is still required as uncrustify
is not ideal (unfortunately), but at least one may rely on it to do the
right thing most of the time (e.g. when sending in a patch).
The style itself is quite different from what we had before but making it
uniform across all the codebase is the key. I also hope that it'll make the
code more readable (YMMV) and less sensitive to further changes.
Implement BSD/Darwin (kqueue) and Windows (ReadDirectoryChanges) mechanisms
for receiving directory change notifications. Use events instead of polling
for changes. Retry file parsing up to 3 times before giving up.
Huge thanks to missionsix for preparing first two versions of the patch.