bandwidthd robust filesystem creation

Make the code that starts bandwidthd check for the correct dirs and symlinks, leave them alone if they are already there, and put them in place if they are missing. This fixes some places where some commands were generating "already exists" warnings, and generally makes sure that whatever someone does at the command line to mess with bandwidthd dirs and links, they will be put back when bandwidthd starts.
Merge pull request #392 from phil-davis/master

bandwidthd robust filesystem creation
Merge pull request #393 from hoerup/master

varnish3: Add gui option to disable backend probing
Merge pull request #394 from hoerup/master

varnish3: Storage size is a mandatory field
haproxy-devel, improvements (but 'breaks' parts current config)
-moved the 'backend' config fields to page where they make more sense without "magic merging" of frontend settings..
-certificate can now be chosen from certificate manager certificates

to find any 'config problems' run "haproxy -c -V -f /var/etc/haproxy.cfg" on a console/ssh session
Merge pull request #395 from PiBa-NL/haproxy-devel_build_tags

haproxy-devel, improvements (but 'breaks' parts current config)
Merge pull request #396 from hoerup/master

Fix for bug #2624
Open the Access Bandwidthd UI in a new tab

The Access Bandwidthd tab takes the user completely out of the pfSense WebGUI interface when clicked. This behaviour is not user-friendly. IMHO it is better to open the Bandwidthd UI in a new tab.
Merge pull request #397 from phil-davis/master

Open the Access Bandwidthd UI in a new tab