-Screwed around with SSE2.

-Added ReleaseSSE2 as a build target.
-LL_VECTORIZE is silly and breaks things...
-Small little tweaks.

I have not tested if the cmake alterations work under linux and darwin. Hollar if broken.

indra/llmessage/llpacketbuffer.cpp

@@ -42,6 +42,9 @@
 
 LLPacketBuffer::LLPacketBuffer(const LLHost &host, const char *datap, const S32 size) : mHost(host)
 {
+	mSize = 0;
+	mData[0] = '!';
+
 	if (size > NET_BUFFER_SIZE)
 	{
 		llerrs << "Sending packet > " << NET_BUFFER_SIZE << " of size " << size << llendl;