QuickPALM: fix NullPointerException

When the full count of threads was not needed, a couple of the elements
in the threads array are still null. Let's not try to join() these.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'quickpalm-npe'

This fixes a NullPointerException when not all available thread slots
were used.

From Ricardo:

	On Sat, 13 Jul 2013, Ricardo Henriques wrote:

	> Hi Johannes,
	> By all means, merge away. Thank you for looking into this.
	> Cheers,
	> -Ricardo

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
fiji.Main: Make sure that the IJ1Patcher has run

This is important when running Fiji in a debugger such as Eclipse's.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'master' of https://github.com/fiji/fiji