VxGW: backport Phase 1 commits

Including the following from master:

b72cdc6 - A man page for VTEP.
f187556 - Fix a typo in the CLI man page for host command.
35aae3f - Implements VTEP-add CLI.
98dd72a - VTEP binding delete accepts only a single binding.
c4fd94d - Replace VTEP's tunnel-zone-id property with tunnel-zone ObjectRef.

Signed-off-by: Galo Navarro <galo@midokura.com>
Merge pull request #211 from srvaroa/1.5.vxgwbackports

VxGW: backport Phase 1 commits
Warns a user when specifying a VTEP name.

This patch implements 'writeable' field of SingleAttr. If the field is
set to False, SingleAttr throws a newly defined UserException when a
user attempts to set a value to a read-only attribute such as VTEP
name and description, causing the command execution to abort and to go
back to the command line evaluation loop.

Please note that though this 'writeable' field hasn't been
implemented, many entities are specifying various fields 'writeable',
thus implementing this feature may have unforeseen impacts.

Fix MN-2510
Merge pull request #213 from midokura/dev/tomohiko/writeable-attr-v1.5/20140708

Warns a user when specifying a VTEP name.
Make router name writable

Fixes: MN-2530
Merge pull request #214 from tomoe/MN-2530

Make router name writable
Merge pull request #210 from alexbikfalvi/v1.5.0

Show the license warning upon startup if MN not licensed
Revert "Revert "Update Bridge and Bridge collection media types to V2""

This reverts commit 18c30cadfb36c7cd71cf4ab8684af427f9baebfb.
Merge pull request #216 from srvaroa/1.5.0.bridgev2

Revert "Revert "Update Bridge and Bridge collection media types to V2""
Output license errors to STDERR

Fixes: MN-2533

Signed-off-by: Alex Bikfalvi <alex.bikfalvi@midokura.com>