improvements to jdbc autocompleter

there are some ideas to improve:

• add type of completion (table, shema, etc...)
• make search case insensitive
• update Meta for each completion request (Ctrl + .).
  meta should be visible always, so need to cut long values (ellipses)
• add a parameter of interpretator with a list of schemas by which to get meta (if empty then all)
• return all completions if can't determine type