fix failing hr_attendance_analysis tests

the tests would fail when run after the 11th of the month
because then the hr.contract created by the demo data would not be valid at the
time of the timesheet.

* change the start date of the contract in the tests
* fix HrAttendance.get_default_calendar to raise an exception when no contract
  is found instead of returning an empty list which caused an AttributeError
fix long line
don't raise exception when no contract found

this would cause a failure at addon installation time.
We keep the initial logic (no error) but return a browse null
instead of an empty list.
Merge pull request #10 from gurneyalex/7.0-fix_hr_attendance_analysis

[FIX] hr_attendance_analysis: Fix tests
fix pep8

line max length now 79 char, not 80
Merge pull request #12 from gurneyalex/7.0-fix-pep8

Fix pep8 line max length now 79 char, not 80 and also Renaming xxxx_pool variables to xxxx_obj which is the generally used convention.
add missing dependency on `project`
fix crash when using timesheet_fulfill wizard

The wizard would crash because the call to create new attendance
was passed a datetime object, not a string.

Fix the code + add test showing the bug is fixed.
Update __openerp__.py

fix indentation and spaces
fix hr.attendance creation

in v7, the field sheet_id of hr.attendance is a function field, so we cannot
write to it.
However, passing a sheet_id key in the context at create time helps the search
a bit.
test timesheet is created with correct values

this required changing the employee, because of
https://github.com/odoo/odoo/issues/2011 which makes employee_fp unsuitable for
testing, and fixing the user used to run the wizard in the test (because the
uid is used to find the timesheet_sheet in the hr.attendance sheet_id function
field).
pep8 fix
fix typo