Add a finish handler to the Servo executor.

This avoids an unnecessary delay in case the browser crashes or exits before
the result is printed.
Merge pull request #48 from w3c/finish

Add a finish handler to the Servo executor.
Setup extra logfile for server
Change logging of a non-fatal problem to warning level.
Merge pull request #50 from w3c/jgraham/log_warning

Change logging of a non-fatal problem to warning level.
fixup! Setup extra logfile for server
Merge pull request #49 from w3c/jgraham/pluggable_logging

Support pluggable logging from wptrunner.
Bump version number for release
Test for self.result_data in ServoTestharnessExecutor.

This fixes a bug introduced by 291fa69beeda50a8c5b790c7a48bf9ebbfd81653 that
made crashes fail the removed assertion.
Merge pull request #51 from w3c/fix-timeout

Test for self.result_data in ServoTestharnessExecutor.
Bump version number for release.
Fixup import of debugger arguments conversion function from mozrunner.
Merge pull request #52 from w3c/jgraham/debugger_fixup

Fixup import of debugger arguments conversion function from mozrunner.
Initial support for running tests with ssl enabled in Firefox.