Warn if no preprocessor used

Thanks to @jasonbekolay for implementation: #65

Fix undefined WeakRef issue

@cyril-sf #64

Improve Element References flow

5.0.5

Improve GC

• Clean lastGlobalRef on destruction of {{create-ref}} modifier by @tniezurawski

Fix params names

Changes made by @wozny1989

Fixes create-tracked-ref

Fixed #52 by @wozny1989

Update minimal ember versions in readme

• Update minimum versions #47 by @backspace

Ember-Modifier 4 support

• #43 by @jelhan
• #44 by @jelhan
• #45 by @jelhan

Ember 4 support

• @rwwagner90 fixed handlebars plugin error #23

Improve callback behavour

🏭 Updated callback behavour (#17) by @lifeart, thaks to @lolmaus