Add patches for block-level quant in theora, -O2 on build, and statically link pthread on Windows

r19351_theora_decode_tables_limit127.patch

+commit cce6158fd963a659b5a2eba4deedacba4e55a540
+Author: reimar <reimar@9553f0bf-9b14-0410-a0b8-cfaf0461ba5b>
+Date:   Sun Jul 5 18:27:39 2009 +0000
+
+    Ensure that the filter limit values do not exceed the maximum allowed value of 127.
+    
+    
+    git-svn-id: file:///var/local/repositories/ffmpeg/trunk@19351 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b
+
+diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
+index 66ac2f9..ad32cc9 100644
+--- a/libavcodec/vp3.c
++++ b/libavcodec/vp3.c
+@@ -2171,8 +2171,13 @@ static int theora_decode_tables(AVCodecContext *avctx, GetBitContext *gb)
+     if (s->theora >= 0x030200) {
+         n = get_bits(gb, 3);
+         /* loop filter limit values table */
+-        for (i = 0; i < 64; i++)
++        for (i = 0; i < 64; i++) {
+             s->filter_limit_values[i] = get_bits(gb, n);
++            if (s->filter_limit_values[i] > 127) {
++                av_log(avctx, AV_LOG_ERROR, "filter limit value too large (%i > 127), clamping\n", s->filter_limit_values[i]);
++                s->filter_limit_values[i] = 127;
++            }
++        }
+     }
+ 
+     if (s->theora >= 0x030200)