[TASK] Improve rendering of nested areas based on viewport
Always break in language view and improve other elements like accordion or tabs without inline style.
Merge pull request #580 from xf-/improve-userbility-flux-grid

[TASK] Improve rendering of nested areas based on viewport
[BUGFIX] BackendConfigurationManager checks correctly for only one TypoScript record
Merge pull request #582 from skorpi/development

[BUGFIX] BackendConfigurationManager checks correctly for only one TypoScript record
[FEATURE] Allow use of flux:form.content without flux:grid

This change adds the ability of the `flux:form.content` ViewHelper to create a default Grid with one row and one column if `flux:form.content` is used outside of `flux:grid`. This also means `flux:form.content` is no longer deprecated but now serves only this purpose instead of its original purpose.

Caveats:

* Adding a `flux:grid` after a `flux:form.content` (obviously requiring the `flux:form.content` to be **outside** `flux:grid` in the first place) will **overwrite the first grid and/or create a second grid which is not automatically fetched from the template but must manually be fetched in a custom Provider class**.
* Using more than one `flux:form.content` in sequence when outside of `flux:grid` will be ignored; only the first occurrence is used.

In other words, use of this feature should be reserved for cases when you only need one content area - for example in custom container elements like the Bootstrap Well element.
[DOC] Document difference of use in Form / Content ViewHelper