fix, PEBKAC, only add new levels when really needed in trie_add_word()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, follow-up, actually insert as many levels as needed in trie_add_word()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, leave room in trie_add_word() for final \nul character

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, nchr slot in alrtscc_t imap is off-by-one

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'core/alrt'

* core/alrt:
  fix, PEBKAC, nchr slot in alrtscc_t imap is off-by-one
  fix, leave room in trie_add_word() for final \nul character
  fix, follow-up, actually insert as many levels as needed in trie_add_word()
  fix, PEBKAC, only add new levels when really needed in trie_add_word()