Client Controls Fixes

[areynold]

Replaces #185.

Fixes #184, #189

To test:

1. In your browser, go to Admin > Client Controls and change the Time Until Welcome Page is Shown to 1 hour.
2. "Seconds" should not be an available option.
3. Click Save, then Save & Apply.
4. SSH in and run ndsctl status. If you see actual nodogsplash data, the fix worked. If the fix didn't work you will see ndsctl: nodogsplash probably not started (Error: Connection refused).
5. Open /etc/nodogsplash/nodogsplash.conf. ClientIdleTimeout and ClientForceTimeout should each be set to 60.
6. In your browser, set Time Until Welcome Page to 1 day. ClientIdleTimeout/ClientForceTimeout should be 1440.

[jheretic]

The correct values seem to be generated in nodogsplash.conf, but there seem to be several other problems. One is that running /etc/init.d/nodogsplash restart actually often causes nodogsplash to crash if it's already running. Also, committing values to its LuCI page also causes errors similar to this:

[3][Thu Mar 6 21:47:34 2014]6971 Can't find target ndsINC in mangle table

shortly before nodogsplash crashes.

[dismantl]

Regarding NDS crashing when running the init.d restart command, we might want to modify the init script. The problem with restarting is that it tries to start a new NDS process before the old one is finished shutting down. I've only had success with /etc/init.d/nodogsplash stop; sleep 2; /etc/init.d/nodogsplash start or something similar.

[jheretic]

This has been superseded by opentechinstitute/luci-commotion-splash#26 and related pull requests.