Fix Bootstrap 4 validation messages not being colored red

[stayallive]

I have not touched the other frameworks because time and not having all the knowledge. However this opens up the possibility to differentiate between validation error help messages and just plain help messages (like a user would post).

Also fixed Bootstrap 4 needing is-invalid instead of has-error and add that class to the actual input element, on the group it has no effect.

Also some fixes to the actual help blocks and matched them to how they're displayed in the documentation, relevant sections:

• https://getbootstrap.com/docs/4.1/components/forms/#help-text
• https://getbootstrap.com/docs/4.1/components/forms/#server-side

Result:

[yannrobin]

Hello,

Any Ideas of when this will be pushed as an update ?

Thanks

[claar]

Fix spaces vs tabs issues with surrounding lines.

edit: Looking closer, it appears the spaces vs tabs issue was just in Github's code review page; checking out the code locally, the indentation is perfect. Sorry about that! Nice job.

[claar]

@yannrobin Thanks for the nudge -- merged and released in 4.1.11.

[yannrobin]

Thanks for that, It will be helpful

[stayallive]

Thanks! :)

[claar]

Thanks for contributing, @stayallive !