LLViewerRegion WIP: Added all headers that are dragged in.

Most in particular llevents.h, which comes along with
the demand that the old events in llevent.h are put
in a namespace LLOldEvents. Made all changes necessary
to compile the rest of the code again (without changing
the actual code: it's still using the old events).

This patch also removes LLStopWhenHandled and LLStandardSignal
from indra/llui/llnotifications.h because those are
moved to llevents.h. That seems to be the only change
to indra/llui/llnotifications.h that isn't floater related,
so I left the rest of that file alone.

indra/llcommon/lleventfilter.cpp

@@ -0,0 +1,166 @@
+/**
+ * @file   lleventfilter.cpp
+ * @author Nat Goodspeed
+ * @date   2009-03-05
+ * @brief  Implementation for lleventfilter.
+ * 
+ * $LicenseInfo:firstyear=2009&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "lleventfilter.h"
+// STL headers
+// std headers
+// external library headers
+#include <boost/bind.hpp>
+// other Linden headers
+#include "llerror.h"                // LL_ERRS
+#include "llsdutil.h"               // llsd_matches()
+
+LLEventFilter::LLEventFilter(LLEventPump& source, const std::string& name, bool tweak):
+    LLEventStream(name, tweak)
+{
+    source.listen(getName(), boost::bind(&LLEventFilter::post, this, _1));
+}
+
+LLEventMatching::LLEventMatching(const LLSD& pattern):
+    LLEventFilter("matching"),
+    mPattern(pattern)
+{
+}
+
+LLEventMatching::LLEventMatching(LLEventPump& source, const LLSD& pattern):
+    LLEventFilter(source, "matching"),
+    mPattern(pattern)
+{
+}
+
+bool LLEventMatching::post(const LLSD& event)
+{
+    if (! llsd_matches(mPattern, event).empty())
+        return false;
+
+    return LLEventStream::post(event);
+}
+
+LLEventTimeoutBase::LLEventTimeoutBase():
+    LLEventFilter("timeout")
+{
+}
+
+LLEventTimeoutBase::LLEventTimeoutBase(LLEventPump& source):
+    LLEventFilter(source, "timeout")
+{
+}
+
+void LLEventTimeoutBase::actionAfter(F32 seconds, const Action& action)
+{
+    setCountdown(seconds);
+    mAction = action;
+    if (! mMainloop.connected())
+    {
+        LLEventPump& mainloop(LLEventPumps::instance().obtain("mainloop"));
+        mMainloop = mainloop.listen(getName(), boost::bind(&LLEventTimeoutBase::tick, this, _1));
+    }
+}
+
+class ErrorAfter
+{
+public:
+    ErrorAfter(const std::string& message): mMessage(message) {}
+
+    void operator()()
+    {
+        LL_ERRS("LLEventTimeout") << mMessage << LL_ENDL;
+    }
+
+private:
+    std::string mMessage;
+};
+
+void LLEventTimeoutBase::errorAfter(F32 seconds, const std::string& message)
+{
+    actionAfter(seconds, ErrorAfter(message));
+}
+
+class EventAfter
+{
+public:
+    EventAfter(LLEventPump& pump, const LLSD& event):
+        mPump(pump),
+        mEvent(event)
+    {}
+
+    void operator()()
+    {
+        mPump.post(mEvent);
+    }
+
+private:
+    LLEventPump& mPump;
+    LLSD mEvent;
+};
+
+void LLEventTimeoutBase::eventAfter(F32 seconds, const LLSD& event)
+{
+    actionAfter(seconds, EventAfter(*this, event));
+}
+
+bool LLEventTimeoutBase::post(const LLSD& event)
+{
+    cancel();
+    return LLEventStream::post(event);
+}
+
+void LLEventTimeoutBase::cancel()
+{
+    mMainloop.disconnect();
+}
+
+bool LLEventTimeoutBase::tick(const LLSD&)
+{
+    if (countdownElapsed())
+    {
+        cancel();
+        mAction();
+    }
+    return false;                   // show event to other listeners
+}
+
+LLEventTimeout::LLEventTimeout() {}
+
+LLEventTimeout::LLEventTimeout(LLEventPump& source):
+    LLEventTimeoutBase(source)
+{
+}
+
+void LLEventTimeout::setCountdown(F32 seconds)
+{
+    mTimer.setTimerExpirySec(seconds);
+}
+
+bool LLEventTimeout::countdownElapsed() const
+{
+    return mTimer.hasExpired();
+}