Minor appveyor config file tweaks.
Reorganize / add comments to appveyor.yml file.
Tweak PowerShell command for easier debugging.
Bumping version to 0.4.5-0.
Move grunt.log into separate grunt-legacy-log module.
Remove no-longer-relevant grunt.log unit tests.
When no new tasks found via .loadTasks method, warn. Closes gh-1059.

* More specifically: warn, instead of error.
Remove "CONTRIBUTING.md" from .npmignore. Closes gh-1093.
Temp fix to grunt.file.delete for gh-1134.

* The issue is with .sync in rimraf@2.2.7, but 2.2.6 still works.
* See isaacs/rimraf#40.
* Hopefully this fixes the build again!
Update rimraf to 2.2.8. Closes gh-1134.