Have you installed the QT Visual Studio addin as specified in the build instructions?
That may or may not have the missing programs. As to libgit2 you need to download an appropriately old version and then follow its build instructions to build it in a directory at the same level as the fritzing source (at least on linux, I’m assuming the same on Windows). I think you may want version 23.3 as 23.4 (which I tried) causes problems possibly due to the api change at 23.4 (which is a back port of a security bug fix). It isn’t clear what libgit2 version Fritzing 0.9.3.b used. You need to do the same with the boost library. You may want to review this forum posting (although the build is on linux).
which is the latest thread from a few months ago on building the current head. On linux I can get this far enough to use gdb to find bugs, but have been tied up on a parts checking script for the last year and not gotten back to trying development yet.
Peter