[DEBUG] libsigrokdecode: Add Python exception dump

Dump the full backtrace on Python exceptions to be able to debug invalid
code.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BUG=none
TEST=none

Change-Id: I065a779e99f2a8c1521cb353190a185a7d9470d5
1 file changed