Better integration with rebar, rebar_base_compiler:ok_tuple/error_tuple
added in compile_model/4
in compile/2 IncludeDirs builded with default "include" and 'i' tuples
from CompilerConfig
Merge pull request #171 from jdsieci/master

Rebar intergration and boss_compiler changes
Merge branch 'master' of https://github.com/ChicagoBoss/boss_db