Update TinyMCE format icon names for alignment styles.

[mauritsvanrees]

Coming from Plone 5.2, you will have 'alignleft', which needs to be 'align-left', etc.

This fix reuses the code that Peter just did for the inline styles in PR #321.

[mister-roboto]

@mauritsvanrees thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[mauritsvanrees]

@jenkins-plone-org please run jobs

[mauritsvanrees]

Jenkins on 6.1 has an unrelated error that was meanwhile fixed in CMFPlone master.
I merge.

[mauritsvanrees]

Last week I accidentally made a release from this branch, instead of master.
I have merge the branch manually into master now.

[davisagli]

@mauritsvanrees Maybe zest.releaser should have a feature to configure a list of allowed branches for making releases, so that it can stop you if you try to do it on a different branch?