simplify eb_get_strline and fix eb_get_contents
simplify eb_get_strline and fix eb_get_contents

* simplify eb_get_strline using buf_putc_utf8
* fix eb_get_contents for non utf8 buffers

dmacvicar/qemacs,dmacvicar/qemacs,dmacvicar/qemacs,dmacvicar/qemacs