Fix copy constructor of default implementation of bit vector
Create default implementation of ranked bit vector.

This class has 'rank' implemented (method 'countBits').
Add comment with license information
Refactored count array
Refactor count array
Merge branch 'implementation-of-rank-and-select' of https://github.com/Wikidata/Wikidata-Toolkit.git into implementation-of-rank-and-select
Implement method to find the position of a value in ranked bit vector
Simplify the method to update the counts
Improve memory use of the array to find the position of a bit value
Split the implementation of ranked bit vector into smaller classes
Use observer pattern
Add toString method to auxiliary types of ranked bit vector
Extend test class to test findPosition method
Improve javadoc
Make minor improvements in javadoc
Rename auxiliary class
Make algorithm a little clearer
New module for test-related code
Updated web and file access helper classes

* Moved classes to util package
* Changed main interfaces from BufferedReader to InputStream
Move mock object code to new testing module

Otherwise one would either need to have a dependency on Mockito for the
utils package or move the mock objects to the test directory of that
package.