docs: Update API descriptions

Author: xlz

doc/mainpage.dox

@@ -1,5 +1,7 @@
 /** @mainpage API Reference
 
+Older versions: [0.1](0.1).
+
 Introduction
 ============
 

include/libfreenect2/frame_listener.hpp

@@ -47,7 +47,7 @@ class LIBFREENECT2_API Frame
   /** Available types of frames. */
   enum Type
   {
-    Color = 1, ///< 1920x1080
+    Color = 1, ///< 1920x1080. BGRX or RGBX.
     Ir = 2,    ///< 512x424 float. Range is [0.0, 65535.0].
     Depth = 4  ///< 512x424 float, unit: millimeter. Non-positive, NaN, and infinity are invalid or missing data.
   };

include/libfreenect2/libfreenect2.hpp

@@ -164,7 +164,7 @@ class LIBFREENECT2_API Freenect2Device
    *
    * FrameListener will receive frames when the device is running.
    *
-   * @return Undefined. To be defined in 0.2.
+   * @return true if ok, false if error.
    */
   virtual bool start() = 0;
 
@@ -173,19 +173,19 @@ class LIBFREENECT2_API Freenect2Device
    *
    * @param rgb Whether to enable RGB stream.
    * @param depth Whether to enable depth stream.
-   * @return Undefined. To be defined in 0.2.
+   * @return true if ok, false if error.
    */
   virtual bool startStreams(bool rgb, bool depth) = 0;
 
   /** Stop data processing.
    *
-   * @return Undefined. To be defined in 0.2.
+   * @return true if ok, false if error.
    */
   virtual bool stop() = 0;
 
   /** Shut down the device.
    *
-   * @return Undefined. To be defined in 0.2.
+   * @return true if ok, false if error.
    */
   virtual bool close() = 0;
 };