Fixes #48: Adopt standard code signing in favor of DSA signing

Thanks to Mattt Thompson (@mattt) for tag-team-ing this with me.

With this change, if your app deploys only to 10.6+, then you can
dispense altogether with the DSA signatures on future updates to your
application: just make sure the "to" version satisfies the "from"
version's Apple code signing requirements. Most of you are probably
already doing that, and if you're not, you should be anyway.

Specifically, Sparkle validates the designated requirement of the "from"
version against the "to" version. By default, as of this writing, that
means that the bundle identifiers must be the same, and that the leaf
certificate of the signature is the same. So if you keep code signing
your app with the same cert, Sparkle will Just Work without any
additional DSA signature nonsense for you to deal with.

Traditional Sparkle DSA signatures will still be honored.

This support has only been extended to updates to the main app bundle.
If you're updating some other bundle, you will have to use DSA signatures
to secure your updates in the future.

***IMPORTANT: previously, Sparkle considered an update "safe" if both the
appcast and update were distributed over https. That is nowhere near as
strong a verification measure as code signing or the old-school DSA
signatures, so with this change, support for unsigned, https-distributed
updates has been removed. If you're targeting 10.6+, start code-signing
your apps if you haven't already, and everything will be fine. If you're
targeting earlier OS Xs, you'll need to start adding DSA signatures to
your appcasts. When you link this changed version of Sparkle into your
app, it will warn you on launch if you are not code signed and do not
have a DSA public key specified in your Info.plist.
Making sure to initialize all Security types
Update to the Brazilian Portuguese localization from Victor Figueriedo
Added kSecCSCheckAllArchitectures to the flags for code signing validation so that inactive architecture binaries are checked as well in the update.
Fixed potential crasher in code signing in the case that the host application is not code signed.
Add Thai localization
Adding Thai localizations to the project.
Fixes #133: Sparkle deleting/replacing the wrong executable when it unpacks

-[SUHost installationPath] can return different values before and after
the installation is performed, because it may attempt to normalize the
installation path--but only if the normalized version of the path isn't
already present. Which it would be after the installation had completed.

Now we only compute the installation path once for the whole installation
process.
Merge branch 'master' into CodeSigning
Fixes #198: Problem with 10.5

Implicitly linking the Obj-C runtime with the 10.7 SDK is causing us to
inadvertently reference libblocks symbols, which don't exist prior to
10.6.
Disable row selection in the system profile table by implementing the table delegate and turning off "Avoid Empty Selection", "Preserve Selection" and "Select Inserted Objects" on the array controller in the nib.
Adding Arabic localization, courtesy Muhammad Azmi Al-Hashemi
Upgraded to LLDB debugger
fixing up the xcode configs to match ours for simpler building
fixed the Debug App Store configuration.. it was misnamed and causing a build error.
Fix warnings
Support for notifications on some updater events
Merge branch 'master' of git://github.com/andymatuschak/Sparkle
Update strings files to standardize ellipsis character (…) instead of three dots (…)
Also change don't to curly quote don’t in dialog.
Update remaining english straight single ' quotes to curly ’ quotes