Bootrom Tools: automated test: Added JTAG error detection
Bootrom Tools: automated test: Added JTAG error detection

Because JLinkExe does not return a non-zero status on failure, we instead
capture its debug spew and check for known failure messages and lack of
certain success messages, throwing an IOError in the case of a detected
error.

Testing Done: Dev. test
Bug Number: SW-982
Review URL: https://reviews.leaflabs.com/r/1479/
Reviewed by: Jun Li

Signed-off-by:  Morgan Girling <980e61e2e2b82c453db57c2e8646c01fbd3318cd@bsquare.com>

projectara/bootrom-tools,gregkh/bootrom-tools,gregkh/bootrom-tools,gregkh/bootrom-tools,projectara/bootrom-tools,projectara/bootrom-tools