DataObjects.Net v4.2.1 and v4.3 RC2

This is my plan on this weekend. v4.2.1 will include all the changes and fixes we've made there after v4.2 release. This is still a stable branch we maintain.

v4.3 RC2 will include all the updates made both branches. There are two important improvements:

• It won't require you to install PostSharp 2.0. This is an option now, if PostSharp isn't installed, it will use integrated one, as before.
• There is DataObjects.Net Project Upgrade Tool simplifying migration from v4.X to v4.3 and helping to reference DataObjects.Net from already existing projects.