Downscale massive PNG files

[luckyrat]

E.g. the 100x100 "icon" at http://www.bloomthat.com/

[kabili207]

Considering the recent addition of high resolution custom icons in KeePass 2.29, it might be better not to downscale the images if the user is running this version.

In fact, it may be a good idea to add support for apple-touch-icons since these are by nature larger than most favicons.

[luckyrat]

Both good points.

There are probably other enhancements that can come about for KeePass 2.29+ but there are two things that mean I can't work on that for the foreseeable future:

1. I just don't have enough spare time to dedicate much to this project at the moment
2. Getting the new code to work for both old and new KeePass is probably going to be painful - it's not actually possible to use the new APIs in 2.29 without crashing for all users of older versions unless we use reflection which is never fun or robust (especially not while retaining support for .NET 2)