Update license headers and add new licenses

- Renamed LICENSE.LGPL to LICENSE.LGPLv21
- Added LICENSE.LGPLv3 & LICENSE.GPLv2
- Removed LICENSE.GPL

Change-Id: I803e1abdc6f126d5251746422e16fff7463f2dff
Reviewed-by: Antti Kokko <antti.kokko@digia.com>
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>
Bump version

Change-Id: Idd9e1d79ccde1c4fe4d5bda0007f6a4c357e5840
Silence warning about unused parameter

It's only used in debug mode.

qjp2handler.cpp:1183:55: warning: unused parameter 'image' [-Wunused-parameter]

Change-Id: I0260f21dbee2105f297af0224e25f14a88ee4557
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Merge remote-tracking branch 'origin/5.3' into 5.4

Conflicts:
	.qmake.conf

Change-Id: I4453973e64dc6488fce35b2eccf98ead5d1006e8
Fix libmng test.

libmng pulls in libjpeg. In turn libjpeg requires that code that uses it should
include stdio.h [0].

[0] <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=461602#10>

So adding the corresponding include before libmng solves the issue.

Change-Id: I7cfbda727ed5b71b668d6597358a5e9c7d8918bb
Reviewed-by: Dmitry Shachnev <mitya57@gmail.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Lisandro Damián Nicanor Pérez Meyer <perezmeyer@gmail.com>