* ROI:
 - getBooleanMask2D(..) returns now an empty mask instead of null.
 - fixed minors bugs.
* Replaced 'Save' by 'Save as' one.
* minors changes on About frame.
* minors changes on javadoc generation.
javadoc update
Merge branch 'master' of https://Stephane-D@github.com/Icy-imaging/Icy-Kernel.git
Javadoc improvements.
* ROIxxStack: fixed issue in bounds calculations.
* BooleanMask: fixed issue in bounds calculations.
* version change.
* minor javadoc change.