Changes

Summary

1. merged
2. detect old log files (early 2016);
3. explicit support for multiple regexes;
4. some derived data fields, to facilitate queries;
5. tuned signature;
6. Automated merge with bundle:/var/folders/9z/l1x9y3bd16x9_70pdp4703jr0000gp/T/SourceTreeTemp.VldMQI
7. Simplification of some proofs. Also key lemmas using !! rather than ! in premises
8. more general pattern;
9. more timing;
10. proper quote (amending 546020a98a91): e.g. relevant for "ISABELLE_BUILD_OPTIONS";
11. suppress build_log_snapshot: too bulky;