Add Ionic skin, from Polarity Viewer

indra/newview/skins/ionic/colors.xml

indra/newview/skins/ionic/manifest.json

indra/newview/skins/ionic/textures/Blank.png

indra/newview/skins/ionic/textures/Nametag_Rect.j2c

indra/newview/skins/ionic/textures/Rounded_Rect.png

indra/newview/skins/ionic/textures/alpha_gradient.png

indra/newview/skins/ionic/textures/arrow_down.png

indra/newview/skins/ionic/textures/arrow_up.png

indra/newview/skins/ionic/textures/avatar_thumb_bkgrnd.png

...ewview/skins/ionic/textures/bottomtray/Cam_Avatar_Off.png

...wview/skins/ionic/textures/bottomtray/Cam_FreeCam_Off.png

...newview/skins/ionic/textures/bottomtray/Cam_Orbit_Off.png

...a/newview/skins/ionic/textures/bottomtray/Cam_Pan_Off.png

...w/skins/ionic/textures/bottomtray/Cam_Preset_Back_Off.png

...ew/skins/ionic/textures/bottomtray/Cam_Preset_Back_On.png

...ew/skins/ionic/textures/bottomtray/Cam_Preset_Eye_Off.png

.../skins/ionic/textures/bottomtray/Cam_Preset_Front_Off.png

...w/skins/ionic/textures/bottomtray/Cam_Preset_Front_On.png

...w/skins/ionic/textures/bottomtray/Cam_Preset_Side_Off.png

...ew/skins/ionic/textures/bottomtray/Cam_Preset_Side_On.png