Push Isac code towards Isabelle standards

Introduce and test a new structure
This task has become fairly convenient with Isabelle/jEdit. Here some notes on details.


 * (1) Collect code for the new structure "New" by cutting from old structures "Old". Cutting avoids confusing duplications. This also causes error messages from signature "OLD" will be helpful in steps to come


 * (2) Collect code until all definitions are present and no error in "New" is remaining.


 * (3) Collect entries for signature "NEW" by cutting from old signature "OLD" and do not autogenerate signature "NEW" from structure "New": that does not avoid duplication and might lead to different entries in the signature. Note, that PolyML does not reliably report signature entries without code in the structure (it only reports differences of the signature between signature and structure).


 * (4) Re-arrange entries in signature "NEW" until there are no errors (mostly due to the requirement to define types ahead).


 * (5) Check structure "Old" and signature "OLD" for remaining errors and remove them.


 * (6) For each entry in signature "NEW" push these changes to the source code separatedly for each entry (the reasons are given below) as follows:
 * (6.1) Query & replace "Old.xxx" with "New.xxx".
 * (6.2) . The reason for this is: Isabelle/jEdit opens updated files like "yyy.zzz" as keeps "#yyy.zzz" in the file system; subsequent updates would involve both files.
 * (6.3) Remove the "yyy.zzz~" files, which Isabelle/jEdit saves for each updated file "yyy.zzz" (use the script "~ ~/src/Tools/isac/CLEANUP"); The reason for removal is: subsequent updates would involve these files, which leads to buffer overflows soon.
 * (6.4) continue with (6.1) for the next change.


 * (7) Push these changes to the test suite in a slightly different way:
 * (7.1) Switch to the test setup by running script "~ ~/zcoding-to-test"
 * (7.2) Look for errors of the "import" files in the  Window. Remove errors by switching back "~ ~/ztest-to-coding" and forth again with "~ ~/zcoding-to-test". This part of the test suite is not run with open structures. See above Pt.(2.1) and Pt.(3.1) respectively.
 * (7.3) Use script "~ ~/test/Tools/isac/CLEANUP" instead of "~ ~/src/Tools/isac/CLEANUP".
 * (7.4) Add "open "New" to "Test_Isac.thy" and "Test_Some.thy".
 * (7.5) All tests run by "ML_File" in "Test_Isac.thy" usually run out of the box, because all structures are opened.