project.properties is the same thing as default.properties, it just got renamed with ADT 14.
And project.properties is in the github repo you linked, therefore it should work out of the box if you have the most recent version of the tools. Otherwise update them.
Quote from the changelog:
default.properties which is the main project’s properties file
containing information such as the build platform target and the
library dependencies has been renamed project.properties.
See build changes in revision 14, at the bottom under "Project Setup"
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