Get ActivityTypes and ProductGroups from the API.
Fixes on PG selector to show the URL correctly
Moved populateATs function for more consistent order inside the source as in runtime execution
Optimized code on populateATs and populateAGs
Optimized populateAGs code to use the group specified on the selected activitytypes
set min height on Selector to display the selector consistently
Merge pull request #97 from SmokyBob/feature/material_design

Issue #76 implementation