Remove final keyword (#42)

Allows developers to extend the class for customised implementations

Static calls check is disabled (#36)

NullData -> NullResource (#32)

Stabilized the API

Improved Full Linkage check (#18)

Linkage (#15)

php70 (#12)

* php70

* php70

Compound Documents (#10)

* Added copyright

* Formatting

* Compound Documents

Interfaces renamed. Copyright added. (#9)

* Added copyright

* Formatting

drop php 7.0