input type=number: min/max as expressions

[witoldsz]

Right now it is not possible to setup min/max values of input field as expressions like:

<input type=number min='{{ evaluateMin() }}'>

only exact, compile-time static values are supported like:

<input type=number min=0>

[witoldsz]

Pull request: #1077
I did not see there is an option to add a pull request to regular issues, closing as #1077 was created.