Merge changes from topic "fdevent_refactor"
* changes:
adb: fdevent: extract Add/Del/SetTimeout.
adb: fdevent: extract Create/Destroy from fdevent_context_poll.
adb: fdevent: move TerminateLoop to fdevent_context.
adb: fdevent: move CheckMainThread logic to fdevent_context.
adb: fdevent: delete FDE_CREATED.
adb: fdevent: move run queue to fdevent_context.
adb: implement fdevent_reset by constructing a new context.
adb: move fdevent implementation out to a separate file.
adb: de-globalize fdevent context.
adb: move fdevent to its own folder.
adb: add superfluous include.