fix test dependency so 'make test ARGS=-jN' works
when loading instance dependencies, seek to original position afterwards

otherwise, SDAI_Application_instance::STEPRead() will crash and burn when the file position changes on it
improve some comments in lazy loading code
delete the array of names after creating a STEPcomplex
reformat some error message code, add one message for complex insts
redo some comments
schema name changed for some p21 tests - update it
remove LIBcopy_constructor() - unused since 1992(!)
indents in generated code
split up a 32-line fprintf
improve comments, whitespace
silence a signed-unsigned warning by using size_t
split ENTITYprint_new() into two, print into different files

* split into ENTITYprint_descriptors(), ENTITYprint_classes()
  * the former is now called from ENTITYprint_cc()
* make some changes to the args (don't pass ComplexCollect, just a bool)
initialize entity iAttrs using eDesc
cleanup
temporary commit
temporary commit 2
add some small schemas and a .p21; should be examined, maybe moved/simplified
some types still print in SdaiAll
cleanup