Blank common and advanced problems now display an inline score of "0 points" upon creation

This resolves an issue discussed earlier in the week concerning inline scores. Blank common or advanced problems currently display an inline score of "NA points" upon creation because they contain no gradable content, and as such, assigning points to these problems is not valid. Sylvia Pierce and @sarina both mentioned it might make sense to switch the "NA" to "0", since there is "zero content" to grade. 

@sarina and @marcotuts, what do you think?