Refactor and unit test PHPWord_Style_Font

[ivanlanin]

For consistency, we will use points instead of halfpoints. The size will be converted to halfpoints during XML writing. I've checked and corrected all usages. I also introduce DEFAULT_FONT_COLOR constant instead of hardcoded '000000'.

PHP_Style_Font is now in 100% coverage.

[Progi1984]

Why do you change again 😉 the default size ?

[ivanlanin]

The "old" default font size was defined in halfpoints. Now we define it in points. It's the same: 10 (points) * 2 = 20 (halfpoints).

[Progi1984]

Could you add a comment to the constant for understanding the unit of the const ? Thanks ;)

[ivanlanin]

Ok. Done. Thanks for reminding.

[Progi1984]

I merge it now :)

[ivanlanin]

Thanks. Should I write the refactoring to the changelog?

[Progi1984]

As you want for this ;) or add it in the next pull request :)

[ivanlanin]

I'll add it to the next request :)

By the way, do we want to remove the underscore prefix for private properties/methods name on this version? I see that's one of the source of error reported by Travis.

[Progi1984]

As you want, but the first step stays unit tests and issues fixing.

[ivanlanin]

Ok. I'll stay with unit tests and issues fixing.