Replaced deprecated $wpdb->escape to esc_sql that causes notices on
strict PHP settings
* pmpro-sponsored-members.php: changed the
  pmprosm_getValuesBySponsoredLevel method that had undefined reference
  to "value" rather than "values"
 Added pmprosm_getUserByCodeID and pmprosm_getSponsor functions.
* Added pmprosm_getUserByCodeID and pmprosm_getSponsor functions.
* Added the discount code and code URLs to the sponsored members checkout confirmation email.
* Added ability for a sponsored code to work on multiple levels. Just pass an array for the 'sponsored_level_id' value in the pmprosm_sponsored_account_levels global.
Merge pull request #3 from alexbiddle/bugfixes

Bugfixes
Merge branch 'master' of github.com:strangerstudios/pmpro-sponsored-members

Conflicts:
	pmpro-sponsored-members.php