Fixed failing LoadDataChangeTest
Moved DiffResultAssertion to more standard package
Added getDefinedChanges() convenience method
ChangeMetaData API improvements
Starting automated tests of Change parameters
Automated tests for all changes' minimum parameters
Removed UnsupportedChangeException in favor of validation checks
Database was set too often in minimumRequiredIsValidSql saved state
Improvements to how required/supported logic is tracked so it is based off the generated Statements.

Moved the "DatabaseList" syntax logic to a reusable method and applied it to all usages of "dbms"
Improving how required and supported parameters are determined
Working on VerifyChangeClassesTest: improving examples, removed now unused referencesUniqueColumn
liquibase.change tests pass
All insites-core tests pass
Performance improvement: save all colums per table instead of re-querying for each column
Performance improvement: if we keep querying for all columns, just get all the columns