Prepare release v0.27

Prepare release v0.27

v0.26:

* Custom TFS check-in notes are not exported to commit message (git-tfs#1004, @EdwinEngelen)
* Log in a file git-tfs actions (git-tfs#999, @pmiossec)
* Add support of `.gitignore` to ignore files in `clone` and `init` commands (git-tfs#897)
* Improve branch point changeset detection (git-tfs#1017 & git-tfs#973, @fourpastmidnight & @jeremy-sylvis-tmg)
* Add support for deleting TFS shelvesets using the shelve-delete command
* Allow using both "--changeset" and "--up-to" options at the same time (git-tfs#1057) to fetch a specific range of TFS changesets
* Added a TraceWarning message when the authors file fails to copy to the cache location (git-tfs#1071)
* Prevent infinite loop when parent changeset cannot be found
* Fix xcopy error on build with spaces in solution path (git-tfs#1092)
* Apply export argument to all branches rather than just the trunk (git-tfs#975)

Release notes for 0.25.0

Make 0.23.0 release notes