XML converter test file

@todo needs more test files to validate XML conversions
XmlConverter fixed building XML from array

- ampersand and left angle bracket are now properly escaped
- fixed building XML containing a single root element
- fixed nodes containing empty elements
Added more tests and example test files
Tests bootstrap-local

Phpunit bootstrap file for testing with local source files
Olap cube limit and offset

Limit and offset as optional arguments in all olap methods
Removed v3 and v5 UUIDs

UUIDs versions 3 and 5 were not used
Minor changes to version 4 generation
Merge branch 'master' of github.com:ngs-doo/dsl-client-php
Fixed logger typo

log=>Log in Requirements.php
Multiple find, history

Multiple find and history are PUT request