Rotation and bugfixes

[ph1p]

• This PR removes the accelerometer feature because it did not work properly. Maybe it will come back later, but currently it is just code that can confuse.
• Added a new way to rotate the led matrix and mapped the positions differently (thanks @atesgoral Faster position lookup #3).
• Memory can now be disabled as it can cause problems on some boards. For example if the memory is readonly.
• The change from Make it clearer the existing webgui.cpp contains a (probably) wrong IP #7 was added.
• The remaining letters were made into a hex array

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TODO: make rotations possible with a transformation matrix #2

[Cabalist]

These PRs look great to merge. :)