Some improvements and bug fixes to traceline.

Some improvements and bug fixes to traceline.

SVG UI:
  - Fix some TODOs about clipping SVG objects to the scene.  This fixes bugs
    where a rectangle is too large and not displayed at all.
  - Fix the calculation of the thread endms done time.  This fixes the thread
    gray background not being drawn for the full length of the thread.

Traceline tracer:
  - Enable PatchCreateThread on XP.  This fixes not having the thread creation
    information output in the JSON files on XP.  Still doesn't work on Vista.
  - Print the manual-quit message to stderr, so it doesn't end up in the JSON.
  - Cast a symbol API callback to compile with both older and newer SDKs.
  - Add two small scripts for breaking apart large JSON files into smaller
    pieces, so that the Python tools can handle processing the smaller files.

[M-A Ruel, 2009-06-08 14:09:23]

mostly rubberstamp lgtm

Especially the ruby part, dude, ruby? I'm pretty sure it's not installed by most
of the people, do you mind rewriting it in python or js? :)

[Dean McNamee, 2009-06-08 14:36:36]

Ok ok, I rewrote it in boring python.

[M-A Ruel, 2009-06-08 14:38:22]

lgtm with optional nits

http://codereview.chromium.org/118377/diff/7/11
File tools/traceline/traceline/scripts/split.py (right):

http://codereview.chromium.org/118377/diff/7/11#newcode16
Line 16: l = sys.stdin.readline()
I think you could have written:
  for l in sys.stdin:

http://codereview.chromium.org/118377/diff/7/11#newcode19
Line 19: if l == "},\r\n":
with this, it'll be more agnostic.
if l.strip() == "},":