Merge branch 'master' into develop
Removed unused TAG field.
Added specific typecast to resolve warning: "non-varargs call of varargs method with inexact argument type for last parameter".
Simplified logic expression.
Improved sample app structure. Make it DRY, baby.
Added button "Upload" to sample app in preparation of new section.
Added sample file for upload testing.
Set up basic Upload skeleton.
Added less restrictive methods to Multipart Builder that allows File additions via InputStream (makes it easier to add Android assets).
Refactored Countable Streams to use long instead of int for its size management.
Implemented File Upload example Activity.
Set project version to 0.5.2.
Merge branch 'release-0.5.2'