[ADD] Most of project module migration
[ADD] Map mail subtypes
[UPD] API docstring
[ADD] Update the projects' aliases with values for new fields
[RFR] Use new, generic value mapping method
[RFR] Refactor alias updates out to 8.0 API method
Add build status badge to README
Merge pull request #65 from StefanRijnhart/8.0-project

[ADD] Migration scripts for the project addon
[REF] flake8
[MRG] resolve conflict
[REF] 'product' use now move_field_many_values_to_one function.
[REF] 'product'. use now 'move_field_many_values_to_one' function;
[REF] manage fast (by sql) and slow (by orm.write function) requests
 to update fields;
[REF] update calls in 'hr_expense' and 'product' migrations scripts;
[REF] pep8.