Verify ML2 type driver exists before calling del

Verifies that an ML2 type driver exists for a given
segment type before attempting to call the release_segment
method on it. Logs an error if a type driver is not
found.

This covers the case where a segment is created with
a given type and then ML2 is reconfigured without
support for that type.

DocImpact
The ML2 documentation should be updated with a warning
that disabling a network type driver and re-enabling
it later may lead to possible DB inconsistencies.

Closes-Bug: #1292102
Change-Id: I65a35abf3ed57347bb6e8fee228f8c0697217c00
(cherry picked from commit af89d74d2961db6a04572375150ad908c9e72e78)
Fixes Hyper-V agent issue on Hyper-V 2008 R2

The vmutils.HyperVUtils class used on versions of Hyper-V prior of 2012
is missing the "remove_all_security_rules" method.

Change-Id: Ib14e643c400b230c912589f9480acf59d6e7b147
Closes-Bug: #1360817
NSX: log request body to NSX as debug

Previously we never logged the request body that we sent to NSX. This makes
things hard to debug when issues arise as we don't actually log the body of
the request that we made. This patch adds the body to our issue request log
statement.

Change-Id: I7d98e3d844ebe565fb5919aac3f9afd5b4040e69
Closes-bug: 1360394
(cherry picked from commit 2bc898ff7a18928e94eb81b24dc99d5cb20eae8a)
BSN: Allow concurrent reads to consistency DB

Allow concurrent reads to the consistency DB since the
database lock the block was originally protecting against
is gone.

Closes-Bug: #1357102
Change-Id: I1618b4046e995c796757e723f99288e486683339
(cherry picked from commit b09c9950649c4c9fffa0b096eb21152cd84fe56f)
Merge "NSX: log request body to NSX as debug" into stable/icehouse
Merge "Verify ML2 type driver exists before calling del" into stable/icehouse
Merge "Fixes Hyper-V agent issue on Hyper-V 2008 R2" into stable/icehouse
Merge "BSN: Allow concurrent reads to consistency DB" into stable/icehouse