TRUNK-5205 Use java8 Base64 instead of xerces
replaced use of org.apache.xerces.impl.dv.util.Base64
with java8 Base64
added small refactorings TestInstallUtil.getResourceInputStream
* extracted private methods to improve readability
* renamed parameter
* use parametrized log message style and remove if since log.info
already checks for the log level
set checkstyle rule: Import from illegal package - org.apache.xerces