Refined and simplified image preloading
Removed width/height from cache lookup (since ImageLoader.get() will use 0,0)
Decreased overdraw in reader post list
Further decreased overdraw in reader post list, first pass at flattening view hierarchy
Fixed for two-column grid layout of post list
* Added selector to post list/grid
* Further flattened post list item layout
* Now detecting whether connection exists before updating posts
* Image pre-load tweaks