Fix bug on input cleared after min/max date set

[cacpgomes]

In a datetimepicker with min or max date, after clear input the datetimepicker stop working. Reproduce the error in [https://jsfiddle.net/cacpgomes/web3h8ks/12/]
. Set a date in #datetimepicker7
. Set a date in #datetimepicker8
. Clear input for #datetimepicker8
. Try to pick a date in #datetimepicker8 - not working

[tonix-tuft]

This project seems to be unmaintained as the maintainer is unresponsive.
I have sent several pull requests, but they all have been ignored.

I have some plans about developing it further, so I have forked both
tempusdominus/core and tempusdominus/bootstrap-4:

• https://github.com/tonix-tuft/tempusdominus/tree/fork - Tempus Dominus Core (fork of tempusdominus/core)
• https://github.com/tonix-tuft/tempusdominus-bootstrap/tree/fork - Tempus Dominus Bootstrap (fork of tempusdominus/bootstrap-4)

They are also available through NPM:

• http://npmjs.com/tempusdominus
• https://www.npmjs.com/package/tempusdominus-bootstrap

In these two forks (I worked on the fork branch on both, not on master) I have updated all the NPM dependencies and build scripts,
added some new features and fixed some bugs I have discovered while using Tempus Dominus.

For now, I have left the master branch in my forks intact and the same as in the original repos, as I was waiting for my PR being merged
in the original repos and I am adding patches/bugfixes and new features on the fork branch in both forked projects.

If you have some pending PR you would like to merge, I invite you to fork my forks instead and we can work
on it together in the free time.

@HaroldPutman already sent me a PR which got merged in tonix-tuft/tempusdominus -> tonix-tuft/tempusdominus#1.

P.S.: I have also created a React version of Tempus Dominus Bootstrap, available here (I hope you enjoy it 😃):

• https://github.com/tonix-tuft/react-tempusdominus-bootstrap - GitHub Repo
• https://tonix-tuft.github.io/react-tempusdominus-bootstrap/ - Demo

[tonix-tuft]

Hello guys,

I have sent all the PRs we have already merged into my two forks (https://github.com/tonix-tuft/tempusdominus and https://github.com/tonix-tuft/tempusdominus-bootstrap)
to the main repo of Eonasdan directly on master.

I wanna thank @HaroldPutman, @pablo-lp and @zondatw for their contribution.

I think that now it makes sense for us to continue to work on this project in my two forks and from the master branch instead of the fork branch I have created and used so far
because I was waiting for @Eonasdan to merge the features we added to its main repo.

But again, as @Eonasdan was and still is unresponsive, I think it would make sense to continue the development from the two forked repos https://github.com/tonix-tuft/tempusdominus and https://github.com/tonix-tuft/tempusdominus-bootstrap now using the master branch instead of fork as the starting point from which to fork the branches for your PRs.

As always, PRs for new features, bugfixes are welcome! Thank you. Stay tuned.