add ffmpeg2.1

+http-parser-2.1.zip
+	for srs to support http callback.
+
+nginx-1.5.7.zip
+	for srs to support hls streaming.
+
+st-1.9.zip
+	basic framework for srs.
+
+ffmpeg-2.1.1.tar.gz
+lame-3.99.5.tar.gz
+libaacplus-2.0.2.tar.gz
+libaacplus-patch-26410-b00.zip
+x264-snapshot-20131129-2245-stable.tar.bz2
+	for srs to support live stream transcoding.
+
+tools/ccache-3.1.9.zip
+	to fast build.
+
+links:
+	ffmpeg: 
+		http://ffmpeg.org/ 
+		http://ffmpeg.org/releases/ffmpeg-2.1.1.tar.gz
+	x264: 
+		http://www.videolan.org/ 
+		ftp://ftp.videolan.org/pub/videolan/x264/snapshots/x264-snapshot-20131129-2245-stable.tar.bz2
+	lame: 
+		http://sourceforge.net/projects/lame/ 
+		http://nchc.dl.sourceforge.net/project/lame/lame/3.99/lame-3.99.5.tar.gz
+	aacplus: 
+		http://217.20.164.161/~tipok/aacplus/ 
+		http://217.20.164.161/~tipok/aacplus/libaacplus-2.0.2.tar.gz
+	aacplus-patch: 
+		http://www.3gpp.org/DynaReport/26410.htm 
+		http://www.3gpp.org/ftp/Specs/archive/26_series/26.410/26410-b00.zip
+