Allow ::/0 for IPv6 security group rules

Nova fails to create a security group rule if ::/0 is used as
value for the cidr field

Fixes: LP bug #1199943

Change-Id: Ifce53dbc9f0740337921491aa752900892f47052
Signed-off-by: Rosario Di Somma <rosario.disomma@dreamhost.com>
Makes _PATH_CELL_SEP a public global variable

_PATH_CELL_SEP is used outside of cells.utils so it should be not be private

Change-Id: I0b06a223b50f7d90007bb44ec7897174ed836ad4
Change get_all_instance_metadata to use _get_instances_by_filters

We need an instance list for invoking check_policy against when calling
get_all_instance_metadata. Since the _get_instances_by_filters
call also returns associated instance metadata, we can use this instead
of db.api.get_all_instance_metadata.

Fixes bug #1192715

Change-Id: Idb005b7227447308a8d060be7aa9ff5c70b5ff44
Support Client Token for EC2 RunInstances

The EC2 API allows users to provide a unique ClientToken in a RunInstances
call. Future invocations of RunInstances with the same ClientToken return
the same response but do not create new instances.

Fixes bug 1188327.

Change-Id: I88d40db3c04355a752474217cdb184cd386d060c
Merge "Allow ::/0 for IPv6 security group rules"
Merge "Change get_all_instance_metadata to use _get_instances_by_filters"
Merge "Support Client Token for EC2 RunInstances"
Merge "Makes _PATH_CELL_SEP a public global variable"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp