Merge branch 'transition-to-omnitools'

Summary:
The content of the functions in this library has been moved to the rKOT
repository, Keruald OmniTools.

The OmniTools destiny is to become an utility library to solve common problems.

This repository is the core of the new library.

To avoid to maintain in parallel two code base, the keruald/globalfunctions
package is now a wrapper offering facades around OmniTools.

As, OmniTools follow modern conventions, minimal version bumps to PHP 7.1.

It's also deprecated, as the PHP development best practices evolve to frown
upon global functions and prefer static classes for helper functions.

This branch merge merges the following commits:

• Switch mb_str_pad to Keruald\OmniTools\Strings\Multibyte implementation
• Switch is_ip, is_ipv4 and is_ipv6 to Keruald\OmniTools\Network\IP
• Switch uuid to Keruald\OmniTools\Identifiers\UUID
• Switch dprint_r and dieprint_r to Keruald\OmniTools\Debugger
• Switch remote address functions to Keruald\OmniTools\HTTP\Requests
• Stablize omnitools library version

Ref T1395

Test Plan: Run tests

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1395

Differential Revision: https://devcentral.nasqueron.org/D1627