firestring_conf_parse() attempts to read a configuration from
and parse the results into a structure that it then returns.
The support configuration format is fairly flexible:
# Configuration file example
# These are comments
variable_name = value
variable_name4="array value 1"
variable_name4="array value 2"
as a variable name is special; it causes firestring to parse the file referenced
by the value, overriding any previous values (although they are still accessible
Returns a pointer to a structure containing the data read from
the config file, or
if the file cannot be opened.