rename re_nextexc() to nextesc()
push_string_literal() corrected
get_tok() corrected to support number literals like ".\d"
v7_stringify() corrected for negative integer numbers
v7_strdup() and v7_init_str() corrected
cosmetic
check_str_re_conv() moved from string.c to util.c
function _conv_to_num() added
corrected type conversion in arith()