Added limit to editable characters in all text entries

[gxhamster]

Added a value to Agenda namespace to change how many characters to accept maximum Default value is set to 64

[dahenson]

Thank you for your contribution! If you could please point this PR at the develop branch, I will test it and review it.

I am working on adding a template for PRs with a checklist so that people are aware that I only accept merge requests to the develop branch for eventual inclusion in official releases.