Token Conditions

Creates a simple Token matching condition plugin for Drupal.

Currently the only places this is used in Drupal Core is the Block Visibility Settings.

Example Conditions:

• Title Contains a string
• Field value contains a string
• Field Value is empty
• Current Node author is current User
• Current Node Author doesn't have a user picture
• Current Node was current in the current month

Drupal nested field tokens are still being work on:
#1195874: Need to figure out how to create nested tokens from the array token type
#1222592: Architecture RFC: Field token architecture

Once this finished it should be possible to use much more complex conditions such as:
A reference entity doesn't have a value for certain field
A referenced entity was created in the current month.