Merge branch 'release0.3.19' into develop
Add debug message.
End transaction immediately when no switch present.
Add test for dispatch to all switch but no switch exist.
Keep command line entry list order.
Refactor .feature
* rename nw_dsl.conf -> network.conf
* Remove Scenario Outline template from Ruby code.
tream switch_manager special in switch daemon.
Merge pull request #297 from y-higuchi/switchd_branching

Refactor switch event forwarding interface
Do not generate temporary files in src/** while running tests.
On `rake travis`, run some specs that doesn't require sudo.
Run non-sudo echo message tests at `rake travis`.
add the check that action-vendor-length is a multiple of 8
Make action_*_to_string to public.
improve argument checking in SetIpTos.initialize()

Only the 6 high-order bits of the ToS octet are allocated to DSCP value.
When it comes to constructing a C structure for OFPAT_SET_NW_TOS action,
there is a respective assertion in function append_action_set_nw_tos().
Once the assertion is triggered, the controller will terminate with a
message:

...trema/src/lib/openflow_message.c:1547: append_action_set_nw_tos:
Assertion `( nw_tos & ~0xfc ) == 0' failed.

A sample code triggering this would be:

send_flow_mod_add(dpid, :actions => [ SetIpTos.new(1) ])

The check added to SetIpTos.initialize() makes sure an exception is
thrown before the invalid value reaches the C function, such that it is
now possible to handle the error at Ruby level.
add body length check to VendorAction.initialize()

For OFPAT_VENDOR the action body length is defined to be a multiple of
8. Add a check to the constructor to make the Ruby layer detect the
error condition rather than the C layer.
Merge pull request #298 from infrastation/develop

improve input checks in Ruby action classes
update unit tests for the new input checks

Add two test cases that expect an ArgumentError to be raised:

* OFPAT_SET_NW_TOS with ToS value 1 (not a multiple of 4)
* OFPAT_VENDOR with body length 9 (not a multiple of 8)
Fix VendorAction's body length check.
Merge pull request #300 from infrastation/develop

update unit tests for the new input checks
Fix the NameError of Trema::PacketQueue (refs #299)