Upgrade qca to version 2.0.3.
Add `--disable-tests` to stop building the unittests and examples.
Tested on Lion with clang and llvm from XCode-4.3.3.
ClosesHomebrew/homebrew#12908.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
QCA aims to provide a straightforward and cross-platform crypto API,
using Qt datatypes and conventions. QCA separates the API from the
implementation, using plugins known as Providers.