BlueJ: download ældre versioner

Small point release to add missing Kotlin class templates

This is a release with many different small improvements to BlueJ's usability, plus a few bug fixes.
Fixed bugs:
- Fixed slowdown bug with Java classes over 5000 lines.
- Fixed bug with terminal sometimes not showing exceptions if the stderr pane was not previously visible.
- Fixed bug with rectangle characters showing up in the documentation view on Windows.
- Fixed bug with assert panel not changing the OK button to enabled (and the field to disabled) when selecting null/not-null as the assertion while recording a test
- Show quick fixes even if the locale is one that supports localised Java compiler error messages (e.g. German)
Improvements:
- The Edit->New CSS File has become Edit->New CSS/Text File and will let you create text files
- Select several lines in the Java editor, right-click and select "Screenshot line(s)". A screenshot of those lines will be put on the clipboard. The lines must all be visible on screen.
- In the Java editor, middle-click the name of any other class to go to its definition/documentation. (Also available on right-click menu.)
- When you inspect a String object, new pane for string content and new "Copy to clipboard" button.
- New "Re-run" button on left side of main window, re-runs last constructor or static method (or JavaFX app) with same parameters. (Compiles first, if needed.)
- The New Class dialog now has a new dropdown: Template or Minimal; the latter lets you create a class/interface/enum/record/etc without anything in the body.
- New checkbox in Preferences, in Interface -> General that lets you turn off re-opening last open projects.
- Slightly increased the space for line numbers to help with four-digit line numbers.
- Terminal window has new "Always on top" menu option.
- Made Cmd-comma open preferences on macOS.
- Ctrl-+ should increase font size on non-QWERTY keyboards.
- Increased default font size to 12 in new installations.
- Line numbers on by default in new installations.
- Editor tabs can be dragged to reorder them in the editor windows.
- Ctrl-scrollwheel on Windows and Linux, and two finger pinch-zoom gesture on all OSes changes the editor font size.
- Changed the default Java editor and terminal font to "Source Code Pro", which supports box-drawing characters.

Release of BlueJ 5.4.2.