Remove sleeps and timed polling from networking

Socket waits now block in select() on the socket plus a wake or cancel
socket (Common/Net/Cancel), so a stop or cancel ends them at once.

- HTTP: cancel flags become net::CancelToken; Connect waits once on all
  addresses, receives wait instead of spinning, no DNS retry sleep.
- Adhoc: the friend finder and adhoc server block on their sockets with
  a wake socket and a deadline; matching runs on a CoreTiming tick
  instead of two threads (savestate section bumped).
- sceNetInet select/poll check without blocking and park the HLE thread,
  re-checked from a CoreTiming event until ready or the emulated
  timeout.
- Vendor the aemu_postoffice client (was a submodule) with no sleeps:
  waits on the socket, close via shutdown and an eventcount, cancelable
  connects, and lock-free session slot claims.
- PortManager waits without a timeout; PSP_InitWait replaces the
  headless boot poll.
- TimeUtil: sleep_us/sleep_ms only outside the core; sleep_precise,
  sleep_random, yield and the Windows timer period are gone.
- Unit test for the socket waits.

Core/HLE/sceHttp.cpp

@@ -92,7 +92,6 @@ HTTPRequest::HTTPRequest(int connectionID, int method, const char *url, u64 cont
 	this->url = url ? url : "";
 	this->contentLength = contentLength;
 
-	//progress_.cancelled = &cancelled_;
 	responseContent_.clear();
 }
 
@@ -121,7 +120,7 @@ int HTTPRequest::getResponseContentLength() {
 }
 
 int HTTPRequest::abortRequest() {
-	cancelled_ = true;
+	cancel_.Cancel();
 	// FIXME: Will sceHttpAbortRequest returns an error if the request was not sent yet?
 	//if (progress_.progress == 0.0f)
 	//	return SCE_HTTP_ERROR_BEFORE_SEND;
@@ -238,11 +237,11 @@ int HTTPRequest::sendRequest(u32 postDataPtr, u32 postDataSize) {
 	}
 
 	// Establish Connection
-	if (!client.Connect(getResolveRetryCount(), getConnectTimeout() / 1000000.0, &cancelled_)) {
+	if (!client.Connect(getResolveRetryCount(), getConnectTimeout() / 1000000.0, &cancel_)) {
 		ERROR_LOG(Log::sceNet, "Failed connecting to server or cancelled.");
 		return -1; // SCE_HTTP_ERROR_ABORTED
 	}
-	if (cancelled_) {
+	if (cancel_.IsCancelled()) {
 		return SCE_HTTP_ERROR_ABORTED;
 	}
 
@@ -259,13 +258,13 @@ int HTTPRequest::sendRequest(u32 postDataPtr, u32 postDataSize) {
 		break;
 	}
 	net::Buffer buffer_;
-	net::RequestProgress progress_(&cancelled_);
+	net::RequestProgress progress_(&cancel_);
 	http::RequestParams req(fileUrl.Resource(), "*/*");
 	const char* postData = Memory::GetCharPointer(postDataPtr);
 	if (postDataSize > 0)
 		NotifyMemInfo(MemBlockFlags::READ, postDataPtr, postDataSize, "HttpSendRequest");
 	int err = client.SendRequestWithData(methodstr.c_str(), req, std::string(postData ? postData : "", postData ? postDataSize : 0), extraHeaders.c_str(), &progress_);
-	if (cancelled_) {
+	if (cancel_.IsCancelled()) {
 		return SCE_HTTP_ERROR_ABORTED;
 	}
 	if (err < 0) {
@@ -274,7 +273,7 @@ int HTTPRequest::sendRequest(u32 postDataPtr, u32 postDataSize) {
 
 	// Retrieve Response's Status Code (and Headers too?)
 	responseCode_ = client.ReadResponseHeaders(&buffer_, responseHeaders_, &progress_, &httpLine_);
-	if (cancelled_) {
+	if (cancel_.IsCancelled()) {
 		return SCE_HTTP_ERROR_ABORTED;
 	}
 
@@ -285,7 +284,7 @@ int HTTPRequest::sendRequest(u32 postDataPtr, u32 postDataSize) {
 		ERROR_LOG(Log::sceNet, "Unable to read HTTP response entity: %d", res);
 	}
 	entity_.TakeAll(&responseContent_);
-	if (cancelled_) {
+	if (cancel_.IsCancelled()) {
 		return SCE_HTTP_ERROR_ABORTED;
 	}