clean-up code

fixes #91, #87
Fix failing tests
Add docblocks
Bug fix

If `DOWNLOAD_ENABLED` is not defined, return false
CS fixes
Ignore composer's vendor directory
Reorganize library files
Fix explicit join bug
Merge pull request #97 from texdc/160_autoload_library

autoload library directories
Conform query style to existing standards
Merge pull request #96 from texdc/160_clean_up_others_mess

clean-up work
Merge pull request #78 from zencart/v160

zc160