* Changes to WEEKNUM and YEARFRAC
The optional second parameter for WEEKNUM can take any of 10 values
(1, 2, 11-17, and 21), but currently only 1 and 2 are supported.
This change adds support for the other 8 possibilities.
YEARFRAC in Excel does not require that end date be before start date,
but PhpSpreadsheet was returning an error in that situation.
YEARFRAC third parameter (method) of 1 was not correctly implemented.
I was able to find a description of the algorithm, and documented
that location in the code, and implemented according to that spec.
PHPExcel had a (failing) test to assert the result of
YEARFRAC("1960-12-19", "2008-06-28", 1). This test had been dropped
from PhpSpreadsheet, and is now restored; several new tests have
been added, and verified against Excel.
* Add YEARFRAC Tests
Scrutinizer reported a very mysterious failure with no details.
project.metric_change("scrutinizer.test_coverage", < 0),
without even a link to explain what it is reporting.
It is possible that it was a complaint about code coverage.
If so, I have added some tests which will, I hope, eliminate the problem.
* Make Array Constant
Responding to review from Mark Baker.
* Merge with PR 1362 Bugfix 1161
Travis CI reported problem with Calculation.php (which is not part
of this change).
That was changed in master a few days ago
(delete some unused code).
Perhaps the lack of that change is the problem here.
Merging it manually.
oleibman