Added configrations for x86 WP8 Core and MVVM projects.
Added new sources refs to WIN81 Catel.Core project.
Merge pull request #13 from Taggersoft/develop

Updates for WP8 and WIN81 projects.
(*) CTL-170 Updated release steps to include generated PDF documentation
Added ReaderWriterLockSlim for all target platforms
(+) CTL-175 It is now possible to customize and replace of IoC components (for example, to use an external IoC container)