This is a major refactoring of the separation-logic example. The main changes are:

- the smallfoot case study has been renamed to "holfoot"
- a lot of the results of the smallfoot case study were generalised to the "variables as resource" level of abstraction
- this generalisation allows much shorter and easier proofs for the remaining results
- new methods for handling conditional execution, while-loops and procedure calls implemented
- generalisation of the concept of ghost variables (e.g. limitation on the possible types of ghost variables removed)
- addition of comments that keep track of the current position in the program, thereby giving
useful feedback to the user during interactive proofs or when a proof-attempt fails
- rewritten automation in order to
- make extensions of the programming and specification language easier
- keep track of location comments
- increase speed
- pretty printing uses styles (i.e. colors, bold fonts, etc.) now
- tree predicate of smallfoot generalised to allow data in trees as well as arbitrary n-ary trees
- holfoot command line tool added