Added support of the SEES clause + improved set comprehension translation

src/main/java/de/tlc4b/TLC4B.java

src/main/java/de/tlc4b/Translator.java

src/main/java/de/tlc4b/analysis/MachineContext.java

src/main/java/de/tlc4b/analysis/StandardMadules.java

src/main/java/de/tlc4b/analysis/Typechecker.java

.../tlc4b/analysis/transformation/DefinitionsEliminator.java

...a/de/tlc4b/analysis/transformation/DefinitionsSorter.java

...de/tlc4b/analysis/transformation/MachineClauseSorter.java

...java/de/tlc4b/analysis/transformation/SeesEliminator.java

...4b/analysis/transformation/SetComprehensionOptimizer.java

src/main/java/de/tlc4b/btypes/PairType.java

src/main/java/de/tlc4b/btypes/SetType.java

src/main/java/de/tlc4b/btypes/StructType.java

src/main/java/de/tlc4b/prettyprint/TLAPrinter.java

src/main/java/de/tlc4b/tlc/TLCResults.java

src/main/resources/standardModules/ExternalFunctions.tla

src/test/java/de/tlc4b/analysis/DeferredSetSizeTest.java

src/test/java/de/tlc4b/analysis/NotSupportedTest.java

...java/de/tlc4b/analysis/SetComprehensionOptimizerTest.java

src/test/java/de/tlc4b/coverage/CoverageTest.java