Issue #2683435 by quietone, Jo Fitzgerald, hussainweb, mikeryan, Steven Jones, alexpott, phenaproxima, Sam152, Pavan B S, michael_wojcik, Prashant.c, heddn, benjy: CCK does not exist in Drupal 7, rename Migrate's cckfield plugins to field plugins

Revert "Issue #2683435 by hussainweb, mikeryan, quietone, alexpott, michael_wojcik, phenaproxima, benjy: Consider renaming Migrate's cckfield plugins"

This reverts commit 24f816a1.

Issue #2683435 by hussainweb, mikeryan, quietone, alexpott, michael_wojcik, phenaproxima, benjy: Consider renaming Migrate's cckfield plugins

Issue #2631736 by quietone, jmuzz, Sam152, svendecabooter, benjy: Cckfield Plugins must distinguish core versions

Issue #2324649 by phenaproxima, svendecabooter, benjy, Berdir: Migrate text fields correctly based on their text_processing setting

Issue #2318281 by tim.plunkett, dawehner | kim.pepper: Provide a standard way to check a plugin is an instance of the required interface.

Issue #2213451 by andypost, bdone, benjy, penyaskito, chx, claudiu.cristea, damiankloip, gregboggs, InternetDevels, jessehs, jhedstrom, marvil07, mikeryan, pcambra, Xano, YesCT: Update Migrate API in core