Purpose
Reads the next input line from the given file into a static buffer. The buffer is allocated with malloc and resized dynamically, but is owned by LQU_fReadLine and should not be free'd or overwritten.
The LQU_StealReadLineBuffer function can be used to obtain the buffer; LQU_fReadLine will allocate a new one the next time it is called.
The given Flags are treated as for LQU_fReadFile, which currently calls this routine directly. Note that, as for LQU_fReadFile, blank lines are skipped if the corresponding flag is given. In this case, LQU_fReadLine will never return a pointer to a blank line, but will continue reading lines from the file until a non-blank one is found.
Returns
a pointer to the line, in Line, and also the number of bytes in the line; -1 is returned on EOF, in which case the Line pointer should not be used.