EN_openX allows an EPANET input file to be opened even if it has errors. This required re-arranging code, mainly in input3.c, so that default values are assigned to an object before its input line is parsed.
Adds an output argument to EN_addnode and EN_addlink that returns the index of the newly added object.
Also refactors the validity check on object ID names.
The newly added `gettitle` and `settitle` functions were moved from the Reporting Functions section to the Project (formerly System) Functions section of epanet2.c and epanet.c.