update INSTALL.md : remove extras/library notes because no more at ZF2
extras/library only valid for ZF1 INSTALL.md : https://github.com/zendframework/zf1/blob/master/INSTALL.md#installation
Maintain alphabetical order of service definitions
added zendframework/zend-json as suggest dependency in Zend\Version to support Zend\Version\Version::getLatest(GITHUB)
double backslash
fix wording
fixed DIRECTORY_SEPARATOR and

if tests running with Netbeans by folders follow should be fixed:
-class usage
-uniqid()
-Server\Fault::setEncoding('UTF-8')
added zendframework/zend-json as suggest dependency in Zend\Version to support Zend\Version\Version::getLatest(GITHUB)
double backslash
[#5191] Remove trailing comma

- invalidates JSON, breaking installation of component via composer
Add Guard traits