Refactoring on owl reasoners and some fixes/improvements

[alkidbaci]

Refactoring/fixes related with issue #79 and #91

• AbstractOWLReasonerEx is merged into AbstractOWLReasoner.

• OntologyReasoner is removed. Logic transfered to FastInstancChekerReasoner.

• FastInstancChekerReasoner renamed to StructuralReasoner.

• Updated documentation in accordance.

• Documentation is no longer published when pushing to develop branch.

• Added is_modified attribute for Ontology class which indicates if an ontology is modified, i.e. axioms are added or removed after this ontology was initialized.

• StructuralReasoner will disable caching and reset if ontology modification is detected in order to avoid inconsistencies.

• Changed operator to logical AND for rendering and parsing facet restrictions.

• Updated tests in accordance with the changes.

[Demirrr]

Thank you. Looking Great. So happy with this PR :)