Updated sample appcast to be appropriate for DSA signatures being req…

…uired.

Fixes 251968

Sparkle now requires custom feed parameters to include a "displayKey" and "displayVersion" key. These will be displayed to the user in the initial permission dialog so that he knows what he's getting.

Bumped version number to 1.5b4. Siiigh...

Bumped Sparkle version number in user agent string.

Merged in fixes to some Tiger warnings.

In an attempt to improve 10.3 support, I've added a new build configu…

…ration: Release (GC-support; 10.5-only). Compile with this if your app uses garbage collection. The normal Release configuration will compile 10.3-compatible-y with no GC support.