Floating versions and incremental build support

Version 1.3.0 introduces support for floating versions for PackageReferences allowing you to specify a version like1.3.* for a package reference and it will resolve to the latest 1.3 version of the specified package available. Thanks to @jeffrosenberg for his contribution on this.

This version also adds incremental build support meaning which should speed up repeated builds. As long as the source files (*.sql) and the project file (.csproj) have the same or an older last modified date as the .dacpac the .dacpac will not be build again. This saves the time needed to rebuild the package. Thanks to @jvilimek for his contribution.