[#31], Improved Zips base on @reinra comments

1. Rename instantiation methods:
 process(file) -> get(file) 
 get()         -> create() 
 
Now to create Zips instance you either get it from a file or create it. 

2. Methods that return Charset aware ZipOutputStream and ZipFile throw
IllegalStateException instead of IllegalArgumentException
[#31] Remove synchronized from Zips.process() and transform()