check for exception when looking up slicing criterion

See merge request program-slicing/e-knife-erlang!4

Ignore constraints: add a new cli flag to toggle the use of constraints when performing a slice

See merge request program-slicing/e-knife-erlang!3

Add missing commits that weren't pushed for previous merge

See merge request program-slicing/e-knife-erlang!2

Stop condition change for slicing

See merge request program-slicing/e-knife-erlang!1

# Conflicts:
#   e-Knife/src/main/java/eknife/EKnife.java

* Statistical functions to build tables

 * Added bencher intra- and inter-procedural suits
 * Added Dockerfile

* Left Recursive Grammars transformed to Right Recursive avoiding infinite T generations with suffix analysis
* Grammar.printGrammarInFile

* Measured the generation time of the different graph edges
* Added EKnife.timedRun to evaluate the slicer against all the possible slicing criteria of a program
* Added intraprocedural bencher suite

* Measured the generation time of the different graph edges
* Added EKnife.timedRun to evaluate the slicer against all the possible slicing criteria of a program
* Added intraprocedural bencher suite

* Repeated recursive grammar states ignored in summary generation
* Increased the number of constraints that the stack can contain to 20
* Slice of 3 benchmarks improved

* LiteralConstraint in switch structures

* LiteralConstraint and its stack behaviour implemented

* Fix CFG absorbent clauses