#571 ToolDef readlines/writefile improvements

• readlines/writefile: use try-with-resources.
• readlines: use UTF-8 encoding, to match writefile. Also, we always use UTF-8, rather than the default (platform) encoding, and especially ToolDef should be platform-independent.
• writefile: different way of handling new lines.
  • Added new optional newline argument.
  • Default of newline is platform, for backward compatibility.
  • Allows preserve for writing text to write raw text.
  • Allows custom specific new lines to be used as well.
  • No preserve when writing lines as then may be get mixed new lines.
• Extended ToolDef documentation for the readlines/writefile tools.

Closes #571 (closed)