ruby: rename history table from 'skima_history' to '_skima_history'
ruby: enhance to support sqlite3
ruby: update messages to print usage for sqlite3
Merge branch 'feature_sqlite3' into ruby
ruby: enhance to support MySQL
ruby: update messages for mysql
Merge branch 'feature_mysql' into ruby
ruby: fix typo
ruby: define 'Skima::DEBUG' and 'Skima.DEBUG='
ruby: enhance to support '-D' and '--debug' option
ruby: change to leave 'skeema/tmp.sql' when debug mode
ruby: make '-D'/'--debug' option public
Merge branch 'feature_debugmode' into ruby
ruby: fix to add ';'
ruby: refactor 'DBMS::Base' around 'protected'
ruby: fix navi message to change 'psql -1' to 'psql'
ruby: change to raise error when argname of short opt is 'N' but argval is not an integer
ruby: change to raise parse error when argname of long opt is 'N' but argval is not an integer
ruby: change command option parser to conver str into int when argname is 'N'
ruby: refactor action classes around command options