Here we insist the file is completely allocated

This function makes sure that the filesystem can accomodate the file
of the given size.

Checks the filesystem free space up against the allocated blocks as a
sanity check.

Uses fallocate if available to preallocate the needed blocks.

If fallocate isn't available, it will write zero bytes if insist is true.

system size

This is to spot obvious typos

This check never worked as intended for several reasons:

- Didn't take the existing file size into account, causing it to
  succeed on first startup but fail on next

- Sparse files were not handled, and can't be handled as we don't know
  where in the file a hole could be and whether truncation actually
  would change the number of blocks used at all

Fixes: #1343

Fixes #1612
Testcase by: 	daghf

waiting list in an attempt to recover.

This also fixes buglet in previous commit which failed to call
CNT_AcctLogCharge()

in play in a way that does not lead to panics.

Spotted by:	Martin
Fixes		#1607

pointer to disappear.

This should survive a distcheck again.

And also don't disable the default compiler optimization.

Do not advance the subject but use the ovector information as offset,
pcre might need to peek back when handling lookbehinds.

Original patch from MegaMaddin via github.

Fixes: #1557