SampleImageLoader: fix compile warnings

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fiji Build: delegate to ImageJ2's MiniMaven

This completes the move of MiniMaven to ImageJ2.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix compiler warnings in Fiji Build

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