List of commits to be cherry-picked for 0.11.3

[ChristianMayer]

• Fix #954 - make datasourceIndex work again as RRD data for a diagram #955
• make sure that no values are send during slider movement when send_on… #971 (in Cherrypick #971 fix slider #972)
• Fix OpenweatherMap #970 - at least check whether it should be cherry picked - note (10.11.19): that plugin seems to be broken at 0.11.x so it might need a backport from 0.12
• Fix open weather map name display #975
• Allow user to reload browser after bad error #978
• fix label overriding by diagram title => needs to generate the #986
• prevent from saving invalid file and loosing all its content #987

And to be cherry picked in develop (0.12):

• escape linefeeds in json string to prevent parser exceptions #1002

[peuter]

I just merged all comments into the first one, because in the issue list only the tasks from the initial comment are shown and this issue seemed to have all tasks resolved.

[ChristianMayer]

Next release is 0.12 - so this issue isn't required anymore