This CL accomplishes a few tasks:

- Modifies zap_timestamp so it works with binaries that don't contain a code-view record (ie: have no matching PDB file).
- Refactors initialization and configuration.
- Allows controlling explicit output paths.
- Allows controlling PE/PDB output individually.
- Adds unittesting of all new features.
- Adds unittesting of ZapTimestampApp.

BUG=
R=sebmarchand@chromium.org

Review URL: https://codereview.appspot.com/159240043