minors
move to PSR4
Merge pull request #67 from cordoval/minor-fix

minor fix
move files
move again
actually it works like a charm
Merge pull request #70 from cordoval/move-to-psr4

move to psr4
plug minor fixes
Merge pull request #72 from cordoval/minor-fixes-again

plug minor fixes
IsNull and IsNotNull should not have a value