Modify the AppVeyor build to allow skip in commit body
Modify the AppVeyor build to allow skip in commit body

By default, AppVeyor only recognises [skip xxx] in the commit title.
This change allows the skip messages to be placed in the commit body.
Recognised keywords are:

- [skip ci]
- [ci skip]
- [skip appveyor]
- [appveyor skip]

And since this doesn't affect Unix:

[skip travis]

OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm