CMS-3904 Make input type Boolean

1. implemented  new 'Boolean.ts' in the new package bool and  class Boolean.java
2. InputView.ts: probably was set wrong value for 'initialValue' , I changed it and inserted a  value into initial property(in previous version value always was empty string)
3. registered new input type in UnputTypes.java 
4. updated FormXmlTest.java and AbstractContentTypeSerializerTest.java, tests-resources updated as well
I checked input with more than one occurrence.
added in config the next values: <occurrences minimum="0" maximum="4"/> and 4 inputs appeared.