config.c fixes

Hi,

[ This should have gone out as a cover letter for the patch series
  but some how I didn't manage to make that work ]

While strace'ing builtin-clone I saw this horror:

... write(3, "remote", 6) = 6 write(3, " = ", 3) = 3 write(3, "o", 1) = 1 write(3, "r", 1) = 1 write(3, "i", 1) = 1 write(3, "g", 1) = 1 write(3, "i", 1) = 1 write(3, "n", 1) = 1 write(3, "\n", 1) = 1 munmap(0xb7f72000, 102) = 0 close(3) = 0 close(3) = -1 EBADF (Bad file descriptor) ...

That's just terrible. And hey, it turns out the code is terrible too. I think the best solution is to just parse up the entire config file up front and keep it in a data structure, make the changes and then write it all out at the end. That makes it cheap to make a series of changes too:

	config = open_config(file);
	set_key(config, key1, value1);
	set_key(config, key2, value2);
	set_key(config, key3, value3);
	commit_config(config);

Or something. Anyway, for 1.5.4 I wrote the following two patches that fixes the 1-bytes writes and the double close.

 config.c |  113 +++++++++++++++++++++++--------------------------------------
 1 files changed, 43 insertions(+), 70 deletions(-)

cheers, Kristian