Branch 3.2.x from master for feature PR testing

[pbiering]

Should be a branch created for 3.2.x to merge reviewed already existing feature PRs while keeping master on 3.1.x for now?

[pbiering]

new branch created: v3.2-devel, merged now

• Hook capability for event changes and deletions #1092

[pbiering]

merged now

• Added support for webcal-subscriptions #1229

[pbiering]

pending

• New Web UI #1329

[pbiering]

v3.2-devel is now again on top of upcoming 3.1.9

[pbiering]

3.1.9 released today, "v3.1-maintain" branch created. Any blockers for merging "v3.2-devel" next?

[pbiering]

branch 3.2-devel merged into master