bcf_hdr_get_hrec() - get header line info
@param type: one of the BCF_HL_* types: FLT,INFO,FMT,CTG,STR,GEN
@param key: the header key for generic lines (e.g. "fileformat"), any field
for structured lines, typically "ID".
@param value: the value which pairs with key. Can be be NULL for BCF_HL_GEN
@param str_class: the class of BCF_HL_STR line (e.g. "ALT" or "SAMPLE"), otherwise NULL
bcf_hdr_get_hrec() - get header line info @param type: one of the BCF_HL_* types: FLT,INFO,FMT,CTG,STR,GEN @param key: the header key for generic lines (e.g. "fileformat"), any field for structured lines, typically "ID". @param value: the value which pairs with key. Can be be NULL for BCF_HL_GEN @param str_class: the class of BCF_HL_STR line (e.g. "ALT" or "SAMPLE"), otherwise NULL