admin-ui: Refactor html that is printed from js

Also, fix apyrgio/synnefo#257
admin-ui: Make resetInputs more adjustable

Now, if we add another input or textarea the reset of their value
should work properly.
admin-ui: Get dynamically the default values of inputs

Apply to contact-modals.
admin-ui: Unify titles in modals
Merge branch 'feature-admin-ui-demo' into feature-admin