Merge pull request #719 from nistormihai/devel

Added missing dependencies.
Merge pull request #720 from nistormihai/devel

LB-1664: As a user, I want my old embeds to keep working after switching...
Merge pull request #721 from nistormihai/devel

LB-1664: As a user, I want my old embeds to keep working after switching...
LB-1664: As a user, I want my old embeds to keep working after switching to the SEO solution

.gitignor the subtree .gitignore for the repo /plugins/embed/