relax timeouts in Terminal console check for kernel

and use kernel_info request to check instead of executions
increase timeouts in test_console

should decrease false failures on slow VMs (travis)
make kernel_timeout configurable in terminal console
single timeout value for pexepect in test_console
apply the same long-timeout logic to kernel tests

as previous commit for test_console
Merge pull request #3817 from minrk/console_test

Relax timeouts in terminal console and tests

avoids failures on slow kernels (especially on test VMs)

uses kernel_info to check if the kernel is alive, rather than executions.