Fixed substitution.
Refactorings and documentation
Throwing error if no sort exists when checking subsorts.
fix race condition with substitution
stop flattening terms that can't be disambiguated by concretization
fix smtlib with no prelude
add java backend version of builtin modules
fix search with multiple results per term
remove undesirable files from samples/java_rewrite_engine directory
update gitignore
remove maude from samples (except agent)
remove user substitution test (in preparation for being replaced by lambda)
fix 1_lambda
fix 2_imp
fix lambda++
fix 4_imp++
fix 5_types
fix simple
fix kool
fix fun