* Charts - Add Support for Date Axis
Fix#2967. Fix#2969 (which had already been fixed prior to opening the issue, but had added urgency for Date Axes). Add ability to set axis type to date axis, in addition to original possiblities of value axis and category axis.
* Update 33_Chart_create_line_dateaxis.php
No idea why php-cs-fixer is complaining. It didn't do so when I first uploaded. I can't duplicate problem on my own system. Not enough detail in error message for me to act. Grasping at straws, I have moved the function definition (which is the only use of braces in the entire script) from the end of the script to the beginning.
* Update 33_Chart_create_line_dateaxis.php
Some comments were mis-aligned. This may be related to the reasons behind PR #3025, which didn't take care of this because this script had not yet been merged.
* Add Support to Chart/Axis and Gridlines for Shadow
Continuing the work from #2865. Support is added for Shadow properties for Axis and Gridlines, and Glow and SoftEdges are extended to Gridlines. Tests are added. Some chart tests are moved from Reader/Xlsx and Writer/Xlsx so that most chart tests are under a single directory.
This is a minor breaking change. Since the support for these properties was just added, it can't really affect much in userland. Some properties had been stored in the form which the XML requires them rather than as the user would enter them to Excel. So, for example, setting the Glow size to 10 points would have caused it to be stored internally as 127,000. This change will store the size internally as 10, obviously making the appropriate conversion when reading from or writing to XML. This makes unit tests much simpler, and I think this is also what a user would expect, especially considering the difficulties in keeping track of the trailing zeros.
* More Tests
Confirm value change between internal and xml.
* Still More Tests
Add a little more coverage, and use a neat trick suggested by @MarkBaker in the discussion of PR #2724 to greatly simplify MultiplierTest.