Major packaging change to work around parallel calls - stopped zipping targets from having direct dependency on 'sf-preprocess-package-config', and instead have 'sf-zip-content' call 'sf-preprocess-package-config' if needed. Changed 'sf-prep' to call a target that wipes out the 'generated' directory. It's not perfect but it gets us going again.

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36d82a2f1f927cbe91926e19c69fe74d9170b7de PDK_2.0.c
633b96a83005daab9464a00b8fcbcfa96a247c26 PDK_2.0.d
cc2965329dd1c545c3cad90c83f2c8cf2bc7e2d6 PDK_2.0.e