Remove "Trig Line" display from Device Manager

Fixes #37

As stated on issue tracker, not all devices utilize a trigger line, so we
need not display it on Manage Devices front panel.  This will help alleviate
confusion that might be caused by displaying the default trigger line
value (which is chosen to be nonsensical).
Allow re-ordering of devices (Resolves #27)

A buttom from Manage Devices launches the OrderDeviceList.vi.  Within a
listbox is present populated with the names of devices.  The contents can
be reordered, and accepting changes results in both the device list and
the table being rebuilt with the new ordering applied.

Removed old code from the sandbox.

Resolves #27.
Add DBLtoMenuItem.vi as a helper for MenuCol

Because users may want to allow variables to select items normally chosen
from a menu, DBLtoMenuItem converts a passed double value n (like from Lua's
Str2DBL.vi) to the round(n)th menu item text (0-indexed).  That is,
passing a value of 0.0 would get the top menu item, 1.0 the next one, etc.
Fixed missing tunnel assignment on DBLtoMenuItem

Forgot to set output to default to empty string on the error case.
addresses #23 request: display start/end values
Merge branch 'master' into add-SRS-Funct-Generator