Merge pull request #15 from brendo/master

Implement scanDatabase for Reference Link and Select Box Link fields
Merge pull request #16 from brendo/master

Fixed the scanDatabase function for RL & SBL
Update readme.md
Update readme.md
Update LICENCE.TXT
Update extension.meta.xml
Update extension.driver.php
Update to use Field constant
Use built in FieldManager method
Add Dynamic Text Group driver (for export)
Add Meta Keys driver (import/export)