Variable monocrome in Cap_pvapi.cpp (Bug #3948)

The flag monocrome is not updated properly in Cap_pvapi.cpp.
The default value is false (a color camera); this is done in function CvCaptureCAM_PvAPI().
In version 2.4.9 and below, if the camera was set to mono8 or mono16, the variable monocrome is not updated (unless a call to setProperty with CV_CAP_PROP_MONOCROME is generated). Hence, the image is treated as a colored imaged. This bug was partly obscured by another bug I've posted that merged three gray frames to a color frame. So in essence, the user gets a color frame (3 channels) but it is black and white.
The fix in version 2.4.9 is simple enough. In function CvCaptureCAM_PvAPI::open( int index ), add monorome=true after mono8 and mono16 switch:

if (strcmp(pixelFormat, "Mono8")==0) {
                grayframe = cvCreateImage(cvSize((int)frameWidth, (int)frameHeight), IPL_DEPTH_8U, 1);

if (strcmp(pixelFormat, "Mono8")==0) {
                monocrome = false;
                grayframe = cvCreateImage(cvSize((int)frameWidth, (int)frameHeight), IPL_DEPTH_8U, 1);

And:

        else if (strcmp(pixelFormat, "Mono16")==0) {
                grayframe = cvCreateImage(cvSize((int)frameWidth, (int)frameHeight), IPL_DEPTH_16U, 1);

        else if (strcmp(pixelFormat, "Mono16")==0) {
                monocrome = true;
                grayframe = cvCreateImage(cvSize((int)frameWidth, (int)frameHeight), IPL_DEPTH_16U, 1);

In version 3.0 the default behavior is setting the camera to mono8. This should arguably fix the problem since the default is OK however in case someone changes the pixel format to mono16 the bug remains. Therefore, a similar fix should be done in 3.0 in the switch case.