Implementing RDP remote scaling and orientation
This PR enables RDP server scaling in HiDPI display and screen orientation, and fixes #969 (closed). Remote scaling and orientation are documented in [MS-RDPBCGR] TS_UD_CS_CORE. Settings are currently not automatically detected from your current monitor: you must manually enable them in remmina global setttings, RDP tab. Orientation: can be 0, 90, 180, 270 degrees. Desktop Scale Factor: scaling of desktop and desktop apps, range from 100% to 500% Device Scale Factor: scaling of metro (appstore?) apps. Works on Win2012R2, windows 10 seems to ignore it. Can only be 100%, 140% or 180%.