Provide a flag to kill webplot

This patch provides a flag for the webplot shell script to kill
the existing webplot process from the command line.

This also requires to register the interrupt handler for SIGTERM
in addition to SIGINT.

BUG=chromium:443539
TEST=Run the webplot script in a chromebook by typing
$ webplot
Then type the following command to kill the webplot process.
$ webplot -k
It should display the message about killing the webplot process.

Change-Id: I3c84d068dea5c3171ebb9bc34af56c5cc40bfc7d
Reviewed-on: https://chromium-review.googlesource.com/246431
Reviewed-by: Charlie Mooney <[email protected]>
Tested-by: Shyh-In Hwang <[email protected]>
Reviewed-by: Shyh-In Hwang <[email protected]>
Commit-Queue: Shyh-In Hwang <[email protected]>
2 files changed
tree: 2f1494150a2759be7a42c702537999779a2129d2
  1. webplot/
  2. OWNERS
  3. setup.py
  4. webplot.sh