Launcher (Windows): only open console by default if the name is debug.exe

We had some cute code that would automatically open the console if the
executable was named ImageJ.exe. The idea was actually to open the
console if it was *not* named ImageJ.exe, but even that was misguided.

Instead, only launch the console if the name is 'debug.exe' which we can
tell users to do easily (it is much easier to rename a file on Windows
than to start it with command-line options).

Noticed by Wayne Rasband.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Launcher: in verbose mode, tell us where you found the JRE

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Launcher (Windows): be verbose when started as 'debug.exe'

The idea of being able to rename the executable to 'debug.exe' for
debugging suggests that we should be much more chatty in that case.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Launcher: let local jre/ have precendence over all other options

The jre/ subdirectory was established as the place where the JRE lives
by the ImageJ 1.x installer.

Obviously, this cannot support multi-platform installations (e.g. a
portable application for all supported platforms).

Hence we need to make sure that the jre/ subdirectory actually contains
a valid libjvm before going with it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Launcher: remember result of the first get_jre_home() call

In verbose mode, it is a little annoying if the same result is reported
a couple of times. Instead, only try to find the JRE once and if none
was found, remember that fact (we already remembered when it was found).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge remote-tracking branch 'github/master'