Expose timeout property for the downloader.
Merge pull request #591 from hsoi/downloader-timeout

Expose timeout property for the downloader.
Bump version to 3.5.2
support arm64
update documentation
changed sizes to NSUInteger
Merge pull request #603 from akhenakh/64bits_support

64bits support (fix #572, fix #504, fix #494)
explicit webp detection
fixed code format
reformat code
upgrade libwebp to 0.4.0
Merge pull request #604 from akhenakh/webp_detect

Webp detect
Merge pull request #605 from akhenakh/upgrade_webp

upgrade libwebp to 0.4.0
use a NSInteger as size (cause we are using -1 as start indicator)
more details about delegate call with -1 NSURLResponseUnknownLength
Merge pull request #606 from akhenakh/64bits_support

use a NSInteger as size (was NSUInteger, was long long) cause we are using -1 (NSURLResponseUnknownLength) in progress callback
reformat code (appcode)
NS_ENUM & NS_OPTIONS
Dot-notation should always be used for accessing and mutating properties. Bracket notation is preferred in all other instances
reformat a long method call