Updates from Bernhard Fischer rep dot nop gmail com

Updates from Bernhard Fischer rep dot nop gmail com
- fix typo in rrd_fetch where rrd_read result was checked against an
  incorrect size.
- in rrd_fetch, drop rrd_head_size in favour of rrd_file->header_len
- in rrd_fetch, make the message "post fetch" unambiguous (now past vs.
  post).
- change usage of param rdwr of rrd_open: allow for RRD_READONLY,
  RRD_READWRITE, RRD_CREAT, RRD_READAHEAD; adjust callers accordingly:
  + rrd_resize needs CREAT
  + rrd_dump may want READAHEAD
- implement FD based I/O in rrd_open, rrd_read, rrd_write, rrd_seek.
- in rrd_update, unify write_RRA_row().
- sort | uniq the -T in .indent.pro (info_t was duplicated)
- add stub of an option to use O_DIRECT to the configury
- in Makefile.am, simplify the "indent" invocation of find:
  My find may not support "-o" resp. "-or" nor braces.
  Using -name "*.[ch]" works everywhere, AFAIK.

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1084 a5681a0c-68f1-0310-ab6d-d61299d08faa