Add support for snmp sync on 3Com 4500 switches.
Merge pull request #43 from rafaeldriutti/master

support for 3com 4500
minor code formatting tweaks
renderDepot: display all containers and mount points (#1081)
cell filter pages rendering speed-up

The MAX_UNFILTERED_ENTITIES config variable used to prevent rendering
large sets of unfiltered results. This was helpful in reducting http
traffic and rendering time in browser, but the database fetching of all
entities of particular realm was performed anyway.

This change disables the database fetching of entities if there is no
filter set, and the resulting set size is greater than
MAX_UNFILTERED_ENTITIES config variable value. This allows to quickly
access to the filtering portlet and add/delete tabs on heavy pages
(objects, racks, IP nets).

getEntitiesCount: retrieves the count of enities of specified realm
renderLocationFilterPortlet: check if $_SESSION['locationFilter'] is set
renderRackspace: try to call renderEmptyResults 2 times: to disable
	fetching and to disable displaying
renderDepot: idem
renderIPSpace: idem,
	also the bug if fixed: 'ipv4net' realm was passed to the
	renderCellFilterPortlet even on the 'ipv6space' page
speed-up the getAllVLANOptions func

getDomainVLANList: new fetching func like getDomainVLANs, but w/o stats
getAllVLANOptions: use new getDomainVLANList, optimize except() code
dictionary: add some Ethernet switches
dictionary: add more Ethernet switches
bugfix: port submit form was broken

renderPortsForObject fix
reverting 206015ec
Added snmp sync support for 3com 4510G-24, cisco SF302-08MP, Linksys SRW248G4
fixContext: remove non-existant global '$page'
port type could be changed even if port is linked

renderPortsForObject: render form controls even if port is linked
getExistingPortTypeOptions: check if port is linked and select only compatible types
handlePopupPortLink: fix broken link in succss msg
dont return showError* result from ophandlers

this technique saved one line of code, but obscured the prototype of
ophandlers and showError* functions.

Changed all occurrences of 'return show*' to 'show*; return;' pairs
0.20.6: cut the release
alter IPV4OBJ_LISTSRC to apply to all object types unless specifically excluded
drop the FileLink table, use EntityLink instead
Merge pull request #48 from rafaeldriutti/master

Added snmp sync support for 3com 4510G-24, cisco SF302-08MP, Linksys SRW248G4
minor code formatting tweaks
add SNMP support for 5500G-EI 48-port (#1095)