Replace pChart library with CpChart

[sgiehl]

CpChart is another fork of pChart that was completely refactored and is compatible with all common PHP versions.

Just a few minor changes were required due to new class / method names.

fixes #11116

[sgiehl]

Note: We need to check if this bug might reappear:

The bug #4206 (GD with JIS-mapped Japanese Font Support) was fixed in this
commit: 516c13d
Changed files: class/pImage.class.php class/pDraw.class.php

Don't have GD with Japanese Font Support running. But can try to recompile GD later

Additionally we could check if we might exclude some files in build script as some files had been removed from the old library.

[mattab]

@sgiehl if you have some time after the other remaining issue (#6111) then +1 to try with the JIS-mapped Japanese Font Support, otherwise we could check and fix it afterwards in 3.0.4

[sgiehl]

Note: Recompiling GD wasn't enough, need to recompile PHP