ANNOTATIONJAVA-283: Update Annotation samples according to changes in front-end
ANNOTATIONJAVA-315: Update Annotation samples according to changes in Viewer v2.4.0
ANNOTATIONJAVA-317: Update use of the deprecated viewer methods in annotation and samples to actual methods
Annotation toolbar isn't shown when application path set to null
ANNOTATIONJAVA-365: Java.Annotation - Error occurs in browser console if set up "useJavaScriptDocumentDescription=false"
ANNOTATIONJAVA-376: Test all GroupDocs.Annotation for Java samples before release library
Merge branch 'master' into v1.6.0

Conflicts:
	README.md
version update
ANNOTATIONJAVA-383: Update functional for work with custom database in all Annotation samples and test samples core functional
Merge branch 'v1.6.0' of https://github.com/groupdocs/groupdocs-annotation-java-web-sample into v1.6.0
ANNOTATIONJAVA-394: Java.Annotation - Toolbar is not shown after specific steps
Small updates