add option to send prefix hint for requesting desired prefix length for delegation

This change adds an option on the interfaces page for sending a prefix hint for the selected delegation size. If enabled, a "prefix" field requesting :: with the appropriate prefix length (64 - dhcp6-ia-pd-len) is added to the "id-assoc pd" entry in the dhcp6c config file. This hint is required for requesting prefixes shorter than /64 from Comcast.
Remove unecessary blockedmacs db and read it directly from config
Set action = pass for configured mac addresses on CP passtrumac
Alix 2D6 crashes upgrade process withou out of diskspace

Updating the the RRD graphs causes two copies of each RRD's XML file to be stored in /tmp.

On Nanobsd, the default /tmp size is 40mb. It doesn't require very many RRD XML dumps before this is exhausted.
Merge pull request #802 from Xon/patch-1

Alix 2D6 crashes during 2.1 upgrade process with an out of diskspace error
Split SSL/TLS into separate checkboxes so that plaintext connections can be made secured by using STARTTLS. Support for SMTPS connections should probably be done away with in future. Fixes #3180
outboundnat, disable checkbox
Merge pull request #803 from PiBa-NL/outboundnat_disable_checkbox

outboundnat, disable rule checkbox
Switch to rw mode before file operations on RFC2136 cache. Fixes #3201
Fix ufslabels.sh logic to avoid trying to convert slices which are already using appropriate labels. Fixes #3207
Merge pull request #795 from razzfazz/ia-pd-hint

add option to send prefix hint for requesting desired prefix length for delegation (for master branch)
Make this name a little more general in case we decide to have multiple similar files.
Fix #3218, reaload filter rules when activate or deactivate dhcpdv6
Fix CP stats generation for concurrent users. Fixes #3225
Include the CP zone in the form parameters if one is defined. Fixes access to concurrent graph on zones other than the first/default.
Add patch from Ermal to fix ifconfig error on gif in certain cases.
Allow multiple valid time servers to be entered in the wizard, as they are allowed under System > General
OpenSSL does not like country codes longer than two letters, so remove these entries that are not actually country codes.
Respect default gateway option when adding a gateway from interfaces page. It fixes #3230
Make sure no extra spaces end up in the parsed IP, it can lead to issues in other places (Easy Rule, etc)