rework mstpctl attribute ordering problem with bridge stp processing

rework mstpctl attribute ordering problem with bridge stp processing

Ticket: CM-6626
Reviewed By: CCR-3768
Testing Done: Tested with testcase specified in bug

There was an earlier implementation for this for 2.5.4 (CCR-3599 a quick
fix for 2.5.4).  This patch re-implements the fix.

This patch essentially handles stp set before and after the port is
processed. It replaces the below commit with the patch in this review

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commit 3af351f0a005236e747913bb499c6165e3ec43a4
Author: Roopa Prabhu <roopa@cumulusnetworks.com>
Date:   Tue Sep 29 10:12:07 2015 -0700

    Fix mstp settings ordering issues when bridge stp is toggled on and
off
    (when mstp settings are specified under the port)

    Ticket: CM-6626
    Reviewed By: CCR-3599
    Testing Done: Tested the problem case mentioned in the bug (Plan to
    re-work the fix a bit for 2.5.5)
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Example:
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auto host1
iface host1
    mtu 9000
    bond-slaves glob swp[25-26]
    bond-mode 802.3ad
    bond-miimon 100
    bond-use-carrier 1
    bond-lacp-rate 1
    bond-min-links 1
    bond-xmit-hash-policy layer3+4
    clag-id 1
    mstpctl-portadminedge yes
    mstpctl-bpduguard yes

auto bridge
iface bridge
    mtu 9000
    bridge-vlan-aware yes
    bridge-ports peerlink host1
    bridge-stp on
    bridge-vids 1000-3000
    bridge-pvid 1

info log stmts:
--------------------
info: host1: ignoring mstpctl-portadminedge config (stp on bridge bridge
is not on yet)
info: host1: ignoring mstpctl-bpduguard config (stp on bridge bridge is
not on yet)
<snip>
info: bridge: processing bridge config for port host1
info: bridge: processing mstp config for port host1
info: executing /sbin/mstpctl showportdetail bridge host1
admin-edge-port
info: executing /sbin/mstpctl setportadminedge bridge host1 yes
info: executing /sbin/mstpctl showportdetail bridge host1
bpdu-guard-port
info: executing /sbin/mstpctl setbpduguard bridge host1 yes

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