doc: add function hashtable_dup in plugin API reference
core: change text in comment of function string_replace_regex
doc: add function string_replace_regex in plugin API reference
doc: add function string_split_shell in plugin API reference
doc: add function string_convert_escaped_chars in plugin API reference
trigger: add options "input" and "output" in command /trigger
trigger: add option "copy" in command /trigger
core: fix completion template used in command completion when first argument in template has pipes