Fix #434: Support "emend." and "emend"

[dimus]

Years for authors in parentheses (original authors with ex) are not consistent here

Mycosphaerella eryngii (Fr. Duby) ex Oudem. 1897 {"name_string_id":"e5a49f2e-c7a2-5ebf-9349-8a36a410ec77","parsed":true,"quality":2,"quality_warnings":[[2,"Ex authors are not required"]],"parser_version":"test_version","verbatim":"Mycosphaerella eryngii (Fr. Duby) ex Oudem. 1897","normalized":"Mycosphaerella eryngii (Fr. Duby ex Oudem. 1897)","canonical_name":{"value":"Mycosphaerella eryngii","value_ranked":"Mycosphaerella eryngii"},"hybrid":false,"surrogate":false,"virus":false,"bacteria":false,"details":[{"genus":{"value":"Mycosphaerella"},"specific_epithet":{"value":"eryngii","authorship":{"value":"(Fr. Duby ex Oudem. 1897)","basionym_authorship":{"authors":["Fr. Duby"],"ex_authors":{"authors":["Oudem."],"year":{"value":"1897"}}}}}}],"positions":[["genus",0,14],["specific_epithet",15,22],["author_word",24,27],["author_word",28,32],["author_word",37,43],["year",44,48]]} e5a49f2e-c7a2-5ebf-9349-8a36a410ec77|Mycosphaerella eryngii (Fr. Duby) ex Oudem. 1897|Mycosphaerella eryngii|Mycosphaerella eryngii|(Fr. Duby ex Oudem. 1897)|1897|2

[dimus]

Getting a year from emend (should be 1968 instead of 2003)

Chlorobium phaeobacteroides Pfennig, 1968 emend. Imhoff, 2003 {"name_string_id":"4513701d-e56b-54d6-84a7-941bf4b62e69","parsed":true,"quality":1,"parser_version":"test_version","verbatim":"Chlorobium phaeobacteroides Pfennig, 1968 emend. Imhoff, 2003","normalized":"Chlorobium phaeobacteroides Pfennig 1968 emend. Imhoff 2003","canonical_name":{"value":"Chlorobium phaeobacteroides","value_ranked":"Chlorobium phaeobacteroides"},"hybrid":false,"surrogate":false,"virus":false,"bacteria":true,"details":[{"genus":{"value":"Chlorobium"},"specific_epithet":{"value":"phaeobacteroides","authorship":{"value":"Pfennig 1968 emend. Imhoff 2003","basionym_authorship":{"authors":["Pfennig"],"year":{"value":"1968"},"emend_authors":{"authors":["Imhoff"],"year":{"value":"2003"}}}}}}],"positions":[["genus",0,10],["specific_epithet",11,27],["author_word",28,35],["year",37,41]]} 4513701d-e56b-54d6-84a7-941bf4b62e69|Chlorobium phaeobacteroides Pfennig, 1968 emend. Imhoff, 2003|Chlorobium phaeobacteroides|Chlorobium phaeobacteroides|Pfennig 1968 emend. Imhoff 2003|2003|1