today i've started with the implementation.
i implemented today the ProjectPersistance class and it passed the tests that i made. i've tested it with the testdriven.net tool, which is a add-in for vs.net. when i run the same tests with nunit. they fail nearly all. i think nunit runs the tests in alphabetically order and not in the order the tests are written in the sourcefile. because for some test i need the datas from a previous test. should i fix that? and make the tests autonomous from the others?
for the compilation of the source files i added an interface ICompile in the data layer. i think thats a good solution, so we can add the compilation for other programming languages in later, later iterations simply. the class CSharpCompile implements this interface and is responsible for the compilation.

@reto:

• the Synchronizer class is the process, which starts the synchronization. the ProjectSynchronizer executes the sanchronization. i think, i should describe this in the design document.
  
• i don't understand what you mean with the renaming from Log to ChangeLog. for me the names are clear. can you make an example?
• your solution for the locking problem sounds good. thanks
• i'll correct the names in the sequence diagrams