Update release process

- Create release
- Upload package
- Update Website button
Update the README.md during the release process
Chocolatey: no need to specify the download url...
Associate tfs workitems with pattern #Workitem_id ( github style )

If Microsoft is doing it with TFS2013 and Git, why can't we do it!?!
cleaning/refactoring tests on checkin options (nothing scary)
Use GitTfsTasks
Fix writing download_button.html
Merge pull request #481 from pmiossec/update_release_process

Update release process
export workitems with github/TFS '#' format to better support import in TFS(Git)
Merge pull request #483 from pmiossec/associate_workitem_github_style

Associate tfs workitems with pattern #Workitem_id ( github style )
Load author file during rcheckin

...because there is fetch of commit even during rcheckin command
Load author file before calling a git-tfs command

- prevent error during reading
- prevent a 2nd read if another file is not specified
- clear collections if should read another file
Reading author file in one place only
Better managing of error when reading author file

Now that the reading is done in only one place, we should :
- stop with an error when an author file is passed and an error occurs
- display a warning if an error occurs when reading the author file in cache
Refactor.
Merge #482
Add release notes for v0.19.0.
Ask for release notes with PRs.
Don't blow up if Auth.targets is missing.
Formatting