Don't change dashboard on admin tenant switch

Switching projects as an admin user currently dumps you back to
the Admin dashboard tab. This change fixes that by adding a 'next'
parameter to the switching URL that points to the default panel
of the current dashboard.

The redirect is to the default panel rather than the current one,
since the next tenant may not have access to the current panel
and we want to avoid kicking a user back to the login screen.

Fixes bug #1072848.

Change-Id: I25b8c0e38945d5db57f5bfe7bb174cdbd66156d5
Prevents flavors to be deleted when reusing a name

Adds an extra check to the EditFlavor form
in order to avoid losing the flavor if an
existing name is setted as the new name.

This control is needed because the current
edit implementation is based in a
delete-create action.

Change-Id: I4251c64fa4719831a1ed949bf95349a350dd303d
Fixes: bug #1133254
Fixes uncaught exception on Add Monitor when unable to retrieve pools

Variable instantiated in a try block referenced outside even when
exception happens in the api call that instantiates the variable.

Fixes: bug #1152770

Change-Id: Ic13db9ed87b2600357b0568ff6d01ef0fe28451c
Merge "Prevents flavors to be deleted when reusing a name"
Merge "Don't change dashboard on admin tenant switch"
Merge "Fixes uncaught exception on Add Monitor when unable to retrieve pools"