oox: remove now unused helper methods (generated code used them in the past)

Change-Id: I532dc4ec24c635b9889d77c37113a8ece2c9b88b
oox: clean up customshapes README and data generator

Change-Id: Ie7ef8cd247dedb2a6ea0a6de249cb05e9056f726
oox: generatePresetsCXX -> generatePresetsData

As it no longer actually generates C++ code, but data.

Change-Id: I9b05f139ca4ad2bcfdbbb4b954ed4e0f2a9bcd8b