ErProof class with LFSC output (#2812)

ErProof class with LFSC output (#2812)

* ErProof class with LFSC output

* Created a TraceCheckProof class
   * parsable from text
* Created an ErProof class
   * constructible from a TraceCheckProof
   * writable as LFSC
* A bunch of unit tests

* Reponded to Mathias's first set of comments.

Credits to Mathias for many of the fixes!

* Responed to Andres's first set, fixed tests

I accidentally deleted a "!" last time, causing stuff to fail.

* Use Configuration::isAssertionBuild

* Clarified comment

* Responded to Andres's 2nd review

* Gaurding against a memory error.
* Renaming a file.
* Aggressively unlinking temporary files.