Support for Timed Loop/structures on Desktop Linux

[bhpowell]

Timed Loops are only supported on Windows and RT, making it difficult to port applications that use it to Linux.

In talking to some NI R&D people, it should be possible to port the RT Linux shared library to desktop Linux. (Perhaps it wouldn't even need to be recompiled, since it's x86.) We also need support in the editor on Linux to allow us to drop the structure.

This seems like low-hanging fruit to at least try to implement.

[bhpowell]

In talking to some _former_ LabVIEW Realtime R&D people, I'm hopeful that all that is needed to implement this is to include the timed loop shared library in the desktop Linux distribution. They said they had it working and their recollection is that the editor feature is automatically enabled if the shared library is found.

I intend to test this once I get hold of the shared library from an x64 RT Linux distribution.