Added new argument to [subscriptionprice] shortcode. The level argument allows users to choose which level to get the price from:

Example:

[subscriptionprice subscription=“1”] is the current behaviour.

[subscriptionprice subscription=“1” level=“1”] is the same as current behaviour.

[subscriptionprice subscription=“1” level=“2”] will select the next level in the subscription.

Note: Index starts at 1, not 0.

git-svn-id: https://plugins.svn.wordpress.org/membership/trunk@1024253 b8457f37-d9ea-0310-8a92-e5e31aec5664