rename vp8/common/skin_detection.[hc] -> vp8_*

some build systems have trouble with duplicate basenames.
vpx_dsp/skin_detection.[hc] were added in:
658e85425 Merge skin detection code in vp8/9.

BUG=webm:1438

Change-Id: Ieaa70b40bda409ec23e6d179b47a930ac6243b05

vp8/common/vp8_skin_detection.c

@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "vp8/common/skin_detection.h"
 #include "vp8/common/alloccommon.h"
+#include "vp8/common/vp8_skin_detection.h"
 #include "vpx_dsp/vpx_dsp_common.h"
 #include "vpx_mem/vpx_mem.h"
 #include "vpx_util/vpx_write_yuv_frame.h"

vp8/encoder/onyx_if.c

@@ -16,7 +16,7 @@
 #include "vp8/common/blockd.h"
 #include "onyx_int.h"
 #include "vp8/common/systemdependent.h"
-#include "vp8/common/skin_detection.h"
+#include "vp8/common/vp8_skin_detection.h"
 #include "vp8/encoder/quantize.h"
 #include "vp8/common/alloccommon.h"
 #include "mcomp.h"

vp8/encoder/pickinter.c

@@ -25,7 +25,7 @@
 #include "vp8/common/reconintra4x4.h"
 #include "vpx_dsp/variance.h"
 #include "mcomp.h"
-#include "vp8/common/skin_detection.h"
+#include "vp8/common/vp8_skin_detection.h"
 #include "rdopt.h"
 #include "vpx_dsp/vpx_dsp_common.h"
 #include "vpx_mem/vpx_mem.h"

vp8/vp8cx.mk

@@ -61,8 +61,8 @@ VP8_CX_SRCS-yes += encoder/ratectrl.c
 VP8_CX_SRCS-yes += encoder/rdopt.c
 VP8_CX_SRCS-yes += encoder/segmentation.c
 VP8_CX_SRCS-yes += encoder/segmentation.h
-VP8_CX_SRCS-yes += common/skin_detection.c
-VP8_CX_SRCS-yes += common/skin_detection.h
+VP8_CX_SRCS-yes += common/vp8_skin_detection.c
+VP8_CX_SRCS-yes += common/vp8_skin_detection.h
 VP8_CX_SRCS-yes += encoder/tokenize.c
 VP8_CX_SRCS-yes += encoder/dct_value_cost.h
 VP8_CX_SRCS-yes += encoder/dct_value_tokens.h