add new util method in IOUtil for zip
add method to get zip entry using bytearray
BS-8905, move page content at engine level
fix zip generation
Merge branch '6.3.x' into 'BS-8725_CustomPage_zip'
fix method to get properties as byte (it was using a bad method of JDK that truncated things)
BS-8905, fix update must throw invalid exception
Merge branch 'release-6.3.2' into 'BS-8725_CustomPage_zip'
fix random test
Merge branch 'release-6.3.2' into 'BS-8725_CustomPage_zip'
Merge branch 'BS-8725_CustomPage_zip' into 'release-6.3.2'