- fixes #30
- Text block indentation affects the final string and each line
  is considered in relation to the minimum indentation used so
  this relative indentation for lines that are more indented than
  the minimum must be preserved across indentation strategies
- added a class to store Text block info across multiple lines
  and pass this across calls in IndentAction when indenting lines
- changed IndentAction.getTextBlockIndentationString() to add any
  additional indentation for the line if it has indentation past
  the minimum for the text block
- added new IndentActionTest15