response filters, main menu item, die after ajax response

[boospot]

Hi There,

In this pull request:

• created filter hook for ajax response if someone want to override.
• if we pass false to parent_slug, we can create main menu item if required
• good practice to add wp_die() after ajax response

Hope it helps.

btw, a perfect piece for plugin and theme authors.

i am adding support for one-click-demo-import in my plugin https://wordpress.org/plugins/utestdrive/

This plugin is also aiming to help plugin and theme authors.

Thanks for making this plugin happen!

[donmhico]

Thank you for creating this PR. However, we won't be able to merge this due to the following reasons:

1. It is unclear what issue / request this PR is solving.
2. The plugin you wished to support is no longer active.
3. File conflicts.

Please feel free to create a new PR.