[Win64] RawTherapee 5.3 Release Candidate 1 for testing

[gaaned92]

RawTherapee_release-5.3-rc1_5.3-rc1-27-g2dbd3074_WinVista_64.zip including all last commits is available at https://drive.google.com/open?id=0B2q9OrgyDEfPS2FpdDAtMVI1RG8