changed listview to gridview on gallery layouts

I am changing listview to gridview, so that gallery layout will show
two columns of photographs in landscape orientation. I believe the
screen looks better that way.
renamed port_gallery to alt_gallery as portrait indication of the prefix
is misleading now.
added random scroll values to gallery items
using a new algorithm to create thumbnails

to have consistent thumbnail sizes, now I check the thumbnail size.
storing portrait and landscape thumbnails separately, which is probably
not a very good idea. I will come back to this idea and find a better
solution.
set different padding values based on version
set full scroll orientation based on position
fix layout padding values
Merge branch 'development'
removed unneccessary layouts
Merge branch 'development'
added a small trick to animate photos on swipe up and down
Merge branch 'development'
updated versionCode: 7