yield with route as div id, add headers package

let me know any issues or anything I should do different.  I know I should probably create a branch and merge for bigger issues.

Created the new file because I didnt think that template helper should go in config.coffee or accounts.coffee.  I dont think there is anyway to somehow target the div by id in the less file programmatically is there? Would be nice so you didnt have to remember to target it everytime, but I would think that would get in to non-meteor LESS compiling stuff.

First github pull request :)