improved some functions to deal with domains and ranges that are a unionOf, and added functions to print categories of saref:Function and of saref:Task

added diagrams for Waste, Collection and Treatment modules in new tabs, as well as a symbology legend for the diagrams I added

closes #8: do not redefine SAREF Core classes

Closes #8 and #15

See merge request !19

Issue 15

See merge request !14

closes #18: delete :contains

Closes #18 and #16

See merge request !17

# Conflicts:
#   ontology/saref4envi.ttl

closes #16: Delete entities related to physical objects

See merge request !18

closes #9, delete definitions of entities not in saref4envi

Closes #9

See merge request !16

closes #12, delete disjointWith axioms

Closes #12

See merge request !15