Signed off contributors

Added in BSD license to files

Partially fixed qualifying the empty set constant with its type
Merge branch 'devel-smt' of github.com:Whiley/WhileyCompiler into devel-smt
Changed copyright author
WyC: minor updates ahead of next release.
Merge pull request #413 from hjwylde/devel-smt

Pulling your changes.  Sorry they didn't make the latest release, but they'll be in v0.3.29, to be released next week!
Merge remote-tracking branch 'origin/devel-smt'

Conflicts:
	modules/wycs/src/wycs/solver/smt/Solver.java
	modules/wycs/src/wycs/solver/smt/Sort.java
	modules/wycs/src/wycs/transforms/SmtVerificationCheck.java