[FIX] Naming scheme
Rename config.php to Config.php
Rename xid/xid.php to Xid/Xid.php
Rename xid/README.md to Xid/README.md
Rename xid/xisbn.php to Xid/Xisbn.php
Rename xid/xissn.php to Xid/Xissn.php
Rename xid/xstandardnumber.php to Xid/Xstandardnumber.php
Rename classify/README.md to Classify/README.md
Rename classify/classify.php to Classify/Classify.php
[FIX] Inconsistent naming
Rename Xstandardnumber.php to XStandardNumber.php
[ADD] Autoloader for easier install
[FIX] Documentation
Merge branch 'dev'