Fix has many relationships.

Closes https://github.com/ChicagoBoss/boss_db/issues/166
An attempt to make dialyzer happy.

It still reports an error with has_many_forms though.
Dialyzer is now happy, correct tree type is emitted depending on the type.
Merge pull request #167 from davidw/has_many_fix

Fix has many relationships.
Added table_exists method

Added table_exists method
Merge pull request #169 from cnaize/master

Added table_exists method
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
Fix link to riakc for use with OTP 17
"HEAD"=>{branch, master} and resolve conflicts
Use specific poolboy commit that fixes OTP17

Deprecated type warning
Make ddb use a temporary repo for OTP17
Accommodate OTP 17 in boss_compiler
Ignore vim files
Back to Concurix fork of ddb (updated for otp17)
Use master branch of epgsql/epgsql.

Conflicts:

	rebar.config
Deal with 'undefined' as a Value. Fixes https://github.com/ChicagoBoss/boss_db/issues/177
Normalize indentation in rebar.config
Add test to .PHONY