improv: Various installer fixes and improvements

img/app_128x128.png

img/app_16x16.png

img/app_256x256.png

img/app_32x32.png

img/app_48x48.png

img/help.ico

serverpackcreator-help/Writerside/topics/img/app_128x128.png

serverpackcreator-help/Writerside/topics/img/app_16x16.png

serverpackcreator-help/Writerside/topics/img/app_256x256.png

serverpackcreator-help/Writerside/topics/img/app_32x32.png

serverpackcreator-help/Writerside/topics/img/app_48x48.png

serverpackcreator-help/Writerside/topics/img/help.ico

spc.install4j