fixed a bunch of missing methods related to FloatToken
extended KernelC with floating point numbers
added smtlib translation for floating point numbers and their operations
used changes from Andrei's pending PR to add option --smt_prelude; added prelude for floating-point
included tests
fixed failing tests
fixed wrong config file and failing maude tests
fixed copyright
Merge branch 'master' into verification-with-floating-point

Conflicts:
	k-core/src/main/java/org/kframework/backend/java/symbolic/SymbolicConstraint.java
	k-core/src/main/java/org/kframework/krun/KRunOptions.java
	k-distribution/samples/kernelc/kernelc-syntax.k
	k-distribution/samples/kernelc/tests/config.xml
	src/main/java/org/kframework/backend/java/util/Z3Wrapper.java
fixed problems left by auto-merging
addressed code review comments
fixed io.k
removed some garbage
second try
fixed a bunch of missing methods related to FloatToken
used --z3-executable for example multiplication_by_addition
Merge pull request #1001 from yilongli/quick-fix-for-float

fixed a bunch of missing methods related to FloatToken
Merge pull request #1000 from yilongli/fixing-issue-995

fixing issue 995
KItem built from KLabelInjection and empty KList should have exact sort
removed dead code related to test generation