Upgrade bootstrap.py
A simple, always succeding isabelle checker
IsabelleChecker: Do not pass if ^*** is found in output
Mention mime.types in README
Avoid script in checker/scripts/execute, escape correctly
Change IsabelleChecker to use use_thy
Cleanup invocation of external tools via execute

* avoid unbuffering via "script", and do as much
  as possible from withing python now,
  most specificall:  timeout handling

Conflicts:
	src/checker/models.py
	src/checker/scripts/execute
	src/checker/scripts/java
	src/settings_local.py
Use correct escape sequence "$@" in src/checker/scripts/execute
Adjust IsabelleCheker to new execute_arglist syntax
Merge branch 'tba13' (Brings in Isabelle support)

Conflicts:
	bootstrap.py
	setup.py
	src/checker/models.py
	src/checker/scripts/execute
	src/settings.py
Isar syntax highlighter
Mehr Isabelle-Highlighting
Typo unatested

Conflicts:
	src/templates/attestation/attestation_list.html
Make highlight_diff more relaxed
More keywords highlighted
Separate isar_decode
Add timeout to isabelle submissions
Fix more Isar keywords
Fix the logic option of the Isabelle-Checker
Improve Isabelle lexer a bit