Create DHCP port for IPv6 subnet

There is a bug in dhcp agent code that when first port is created
in an IPv6 subnet, DHCP port is not automatically created.

This fix resolves this problem by removing the IP version check
in configure_dhcp_for_network method.

Change-Id: If3f405d367a7099d9f33d72d11ffcb7a393abe23
Closes-Bug: #1367500
tox.ini: Avoid using bash where unnecessary

Switch to sh, which is hopefully more ubiquitously available than bash.

A recent change (commit 085a35d657cf0fa41a402f2af66c4beaa0f60db2)
introduced bash dependency for "tox -e pep8".  It broke my environment,
where bash is not available.  This change aims to restore it.
As far as I undestand, the change in question doesn't actually need
the specific shell dialect.  So switch to sh, which is expected to be
available for any POSIX-like systems, would improve the situation.

Closes-Bug: #1382327
Change-Id: Ie023d2265d9949a3e3721f03e865e4acfb460de2
Only resync DHCP for a particular network when their is a failure

The previous implementation will loop through and restart the dhcp
process for all active networks any time there is an exception calling
a dhcp driver function. This allows a tenant who can create an exception
to cause every dhcp process to restart. On systems with lots of networks
this can easily take longer than the default resync timeout leading to a
system that becomes unresponsive because of the load continually restarting
causes.

This patch restarts only dhcp processes related to the network on which
operations are failing. It should be noted that if there was some kind
of missed notification for a subnet update, the previous implementation
may have incidentally fixed it by restarting everything on the off
chance that something else caused an exception, but obviously relying
on that would be a bad idea as exceptions should be, well, exceptional.

Closes-bug: #1384402

Change-Id: I0b348a1657a7eb3a595f9bf6b217716a37ce38c6
Imported Translations from Transifex

For more information about this automatic import see:
https://wiki.openstack.org/wiki/Translations/Infrastructure

Change-Id: I25a1b72a78a94e00b28e5d128b5be591fe565b3c
Rename constant to a more appropriate name

The DB_MAX_RETRIES implies that a query will be
retried that many times. 'retry' means it happened
once before. In the current code, if DB_MAX_RETRIES
is set to 1, the query won't be retried at all.
If it's set to 0, the query won't even be run.

This constant should actually be called DB_MAX_ATTEMPTS
to indicate that the variable includes the first try.

Change-Id: I13f088ffa38c40db7fd297173e892b4ad5c7fadd
Detect if iproute2 support SR-IOV commands

Add sanity_check that 'ip link' command supports VF management and
link state changes of VF by parsing 'ip link help' command output.

Co-authored-by: Samer Deeb <samerd@mellanox.com>
Closes bug: 1349302

Change-Id: I5a72a9061a76c39960076f078905371f07069431
Merge "Only resync DHCP for a particular network when their is a failure"
Merge "Rename constant to a more appropriate name"
Merge "Imported Translations from Transifex"
Merge "Create DHCP port for IPv6 subnet"
Merge "tox.ini: Avoid using bash where unnecessary"
Merge "Detect if iproute2 support SR-IOV commands"