revert project.xml and update ImageUtils to reference opencv_ffmpeg 2.4.13

Core/src/org/sleuthkit/autopsy/coreutils/ImageUtils.java

CoreLibs/nbproject/project.properties

CoreLibs/nbproject/project.xml

thirdparty/opencv/README.txt

thirdparty/opencv/ext/opencv-248.jar

thirdparty/opencv/lib/amd64/opencv_ffmpeg248_64.dll

thirdparty/opencv/lib/amd64/opencv_java248.dll

thirdparty/opencv/lib/i386/opencv_ffmpeg2413.dll

thirdparty/opencv/lib/i386/opencv_ffmpeg248.dll

thirdparty/opencv/lib/i386/opencv_java2413.dll

thirdparty/opencv/lib/i386/opencv_java248.dll

thirdparty/opencv/lib/i586/opencv_ffmpeg2413_64.dll

thirdparty/opencv/lib/i586/opencv_ffmpeg248_64.dll

thirdparty/opencv/lib/i586/opencv_java2413.dll

thirdparty/opencv/lib/i586/opencv_java248.dll

thirdparty/opencv/lib/i686/opencv_ffmpeg2413_64.dll

thirdparty/opencv/lib/i686/opencv_ffmpeg248_64.dll

thirdparty/opencv/lib/i686/opencv_java2413.dll

thirdparty/opencv/lib/i686/opencv_java248.dll

thirdparty/opencv/lib/x86/opencv_ffmpeg2413.dll