add the handling logic for Receiving image from other apps (like camera,
gallery, etc).

NOTE: there is a "bitmap too large to be uploaded into a texture" need
to fix. The app will crash directly when the received image is too
large.
add trial android properites 
 - hardwareAcelerate="false"
 - largeHeap="true"
into application settings but comment them out
works (mainly ui tweak):
1.Remove the title bar in Palette Card
2.Add border on them
3.Click on image to fade in-then-out the title buttons
tweak palette card's color (still not quite good tho...)
refacotr on k-means processor to remove *all* color related info from
KMeansprocessor entirely. And to add its handling logic into
PaletteDataHelper.

so the k-means algorithm in KMeansProcessor is a completely generic and
data-indenpendent implementation finally...
introduce the kpp algorithm but comment it out for now as it is not
quite stable (or maybe not quite correct...)

and change the maximum k-mean iteration from 15 to 99 for some special
case that it needs to run many rounds to finish the k-mean process...