unify permissions check for VLAN changes

The VLAN permissions logic from authorize8021QChangeRequests
(functions.php) was duplicated in getAccessPortControlCode
(interface.php). New function nativeVlanChangePermitted now used to
check access ports VLAN permissions. It calls the
authorize8021QChangeRequests in turn.

Also, the overriding hook added into the authorize8021QChangeRequests.
gateways/telnet: fix buffering issues

command prompt is now displayed before reading next input command
Line-buffering of STDOUT is disabled to allow debugging in terminal
gateways/telnet: reindent to tabs
queryTerminal: extend prompt regexp for air12
link status, MAC list support for ExtremeXOS

new handlers: xos12ReadInterfaceStatus, xos12ReadMacList
new dictionary items for Edge-Core AS* switches
fix id conflict in dictionary

two different items had the 2142 id. Renumber one of them.
add some new UCS models

2 of the blades were already in the dictionary.
fix device id regex

Symbol '_' is often used in local names, despite of RFC.
Version number of Debian wheezy is 7, not 7.0.

"Debian 7.0 (wheezy)" is not correct: the current wheezy point release
is 7.5; wheezy itself should have the single digit version number 7.
dictionary: group some Sun entries (#1295)
proxyMuninRequest(): fix spotEntity() call

Use ID of the current object and not of the specified Munin server,
otherwise this triggers an exception or uses irrelevant domain suffix
for the image URL.
restore the r/o DB access semantics in LDAP auth

The commit "70057f4 remember last successful LDAP server" broke the
semantics that DB write attempts did not occure when
$LDAP_options['cache_expiry'] was 0.

It is possible to set-up mysql replication and use RT in read-only mode
on a slave server with LDAP authentication, but LDAP caching must be turned
off.

This commit makes authenticated_via_ldap(), queryLDAPServer() funcs
to check the cache_expiry LDAP option before writing to the DB. Thus,
the "last successful LDAP server" does not work any more when LDAP caching
is disabled.
serializeTags(): use HTML entity, not Unicode char