added optional software-based histogram equalization to ptgrey driver
added optional software-based histogram equalization to ptgrey driver

openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro