allow meteor to be run from subdirectories
allow meteor to be run from subdirectories

Meteor can be run from subdirectories of the root project, as well as the root of the project.  When run in subdirectories, fast-render was not compiling successfully as it was attempting to find `.meteor/packages` somewhere where it doesn't exist.

This is a rough replication of Meteor's app directory identification code, and should successfully determine the correct location to look for the iron-router package, even when run in a subdirectory.
mquandalle/meteor-fast-render,joegoldbeck/fast-render,NIKKTTO/fast-render,meteorhacks/fast-render,avalanche1/fast-render,kadirahq/fast-render,readFOLD/fast-render,mquandalle/meteor-fast-render,modulexcite/fast-render,AnthonyAstige/fast-render