fix(hyperdrive.php): add stability and security improvements
fix(hyperdrive.php): add stability and security improvements

some scripts were missed when they should've been included, now fixed.
corrects a bug in deduplication logic.
improves security with unauted abend and elimination of globals.
outputs plugin version info into the markup for easier debugging.
introduced new utility function to help cover a gap in PHP7 operators.

resolves #23
fixes #7

[*] Access $wp_scripts via wp_scripts() rather than directly.

The wp_scripts() function will initialise $wp_scripts if it has not already been set, before returning $wp_scripts.

[+] Security: Don't allow the plugin to be accessed directly.

[*] Made changes to in_multi_array() as requested.

[*] Add Hyperdrive version as a constant and output as a comment.

Useful for debugging and knowing which version of the plugin users have installed; will also be handy when the plugin has an admin UI.

[-] Remove strict logic from in_multi_array(), it's a bit overkill for the use case.

[-] Tighten up in_multi_array() logic.

[o] Corrected styling.

comfusion/hyperdrive,comfusion/hyperdrive