ruby: change 'BaseSkeleton#_section_vars()' to take options
ruby: change 'DBMS::SQLite::Skeleton#_section_xxx()' to take options
ruby: change 'DBMS::PostgreSQL::Skeleton#_section_xxx()' to take options
ruby: change 'DBMS::MySQL::Skeleton#_section_xxx()' to take options
ruby: enhance 'new' action to take '--table', '--column', '--index', and '--unique' options
ruby: enhance 'new' action to support 'tbl(col)' style as well as 'tbl.col'
Merge branch 'feature_newtable' into ruby-dev
ruby: fix 'up' action to save down sql into history table
ruby: update 'README.md'
ruby: fix to use 'WHERERE VERSION = ?' instead of 'wehre version = ?'
ruby: change 'string' data type to 'text' in SQLite3
ruby: change 'create table' statement in SQLite3 not to convert 'TIMESTAMP' to 'DATETIME'
ruby: remove obsolete methods
ruby: tweak error message to add '## ' as prefix
ruby: fix to remove extra 'return'
ruby: refactor to share line format of history file
ruby: update 'README.md'
ruby: add help message of 'unapply -x' which is not implemented yet
ruby: update 'README.md'
ruby: update 'README.md' for release 0.2.0