Merge branch 'master' into GT-16

Conflicts:
	api/src/main/java/org/cru/godtools/api/images/ImageSet.java
	api/src/main/java/org/cru/godtools/api/packages/GodToolsPackageRetrievalProcess.java
	api/src/main/java/org/cru/godtools/api/packages/utils/FileZipper.java
	api/src/main/java/org/cru/godtools/api/translations/GodToolsTranslationRetrievalProcess.java
	api/src/test/java/org/cru/godtools/api/packages/utils/GodToolsPackageShaGeneratorTest.java
	domain/src/main/java/org/cru/godtools/domain/packages/PackageStructure.java
	domain/src/main/java/org/cru/godtools/domain/packages/Page.java
	domain/src/main/java/org/cru/godtools/domain/packages/PageStructure.java
	migration/src/main/resources/Packages