Valgrind updates

Hi,

it is real late now, so I am uncomfortable sending off a new patch series (I _know_ that I'll just introduce a stupid bug or forget to write a commit message or whatever). In case you are interested in the current progress, you know where my branches are.

The changes I made:

- added t/valgrind/templates to t/.gitignore, too,

- split out the valgrind-unrelated parts that Peff complained about,

- added some more suppressions I needed,

- added a mode whereby the tests' results are written to test-results/,

- provided a Makefile target for further convenience,

- added a script to coalesce the valgrind results by backtrace,

- split out a patch that lets --valgrind imply --verbose, and

- ran the scripts several times, which is a PITA because one run takes 5.5 
  hours (and the first time I forgot to redirect stderr, ouch, thus the 
  test-results/ patch).

I have an output from a previous full run, albeit it was done with an earlier version of the valgrind patch series I was not comfortable with, so I will not send it here. Besides, it is 300K (bzip2 -9 reduces that to 20K), and I am sure you don't want to have it.

Just that much, most of the backtraces are pretty repetitive. In fact, I think most if not all of them touch xwrite.c (I got other errors from my patches, as I expected).

==valgrind== Syscall param write(buf) points to uninitialised byte(s) ==valgrind== at 0x5609E40: __write_nocancel (in /lib/libpthread-2.6.1.so) ==valgrind== by 0x4D0380: xwrite (wrapper.c:129) ==valgrind== by 0x4D046E: write_in_full (wrapper.c:159) ==valgrind== by 0x4C0697: write_buffer (sha1_file.c:2275) ==valgrind== by 0x4C0B1C: write_loose_object (sha1_file.c:2387) ==valgrind== by 0x4C0C4F: write_sha1_file (sha1_file.c:2418) ==valgrind== by 0x46DBB8: update_one (cache-tree.c:348) ==valgrind== by 0x46D8CF: update_one (cache-tree.c:282) ==valgrind== by 0x46DCCA: cache_tree_update (cache-tree.c:373) ==valgrind== by 0x46E2B5: write_cache_as_tree (cache-tree.c:562) ==valgrind== by 0x4662D4: cmd_write_tree (builtin-write-tree.c:36) ==valgrind== by 0x404F37: run_command (git.c:243) ==valgrind== Address 0x713dc23 is 51 bytes inside a block of size 195 alloc'd ==valgrind== at 0x4C2273B: malloc (in /usr/local/lib/valgrind/amd64-linux/vgpreload_memcheck.so) ==valgrind== by 0x4CFFCC: xmalloc (wrapper.c:20) ==valgrind== by 0x4C0A33: write_loose_object (sha1_file.c:2362) ==valgrind== by 0x4C0C4F: write_sha1_file (sha1_file.c:2418) ==valgrind== by 0x46DBB8: update_one (cache-tree.c:348) ==valgrind== by 0x46D8CF: update_one (cache-tree.c:282) ==valgrind== by 0x46DCCA: cache_tree_update (cache-tree.c:373) ==valgrind== by 0x46E2B5: write_cache_as_tree (cache-tree.c:562) ==valgrind== by 0x4662D4: cmd_write_tree (builtin-write-tree.c:36) ==valgrind== by 0x404F37: run_command (git.c:243) ==valgrind== by 0x4050E4: handle_internal_command (git.c:387) ==valgrind== by 0x4051CA: run_argv (git.c:425)

which can be reproduced by running t0000-basic.out in valgrind mode.

Good night, Vietnam, Dscho