[1.3.x Blocks] Updated Blocks module for HtmlBlock editor hooking

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | -
| Fixed tickets | #1726
| Refs tickets  | -
| License       | MIT
| Doc PR        | -

Updated the Blocks System module for the 1.3.x branch with a new version and Hook enabling which makes usage of Scribite 5 possible. Hooks for the HTML block could have been there already, but in previous version of Scribite this worked also by manually activating Scribite.
Merge pull request #1743 from espaan/1.3

[1.3.x Blocks] Updated Blocks module for HtmlBlock editor hooking