Fix group form entering a user with keyboard - return twice would submit the form
'Return' in the linker should not invoke the create form as the user may not have permissions to create
Make subject and agent permissions available as distinct roles for each
add a migration to add the new manage subject and agent permissions to the appropriate groups
Merge pull request #728 from hudmol/seperate-roles-for-updating-agents-subjects

[Delivers #62805480] Seperate roles for updating agents subjects