Removed or annotated existing commented-out code

Clean up logic for saying emergency text.

Previous code didn't properly check for if speech was enabled.

Some functionality was lost, will need to be fixed in a later commit.

Therefore Mouse3DInput has been changed to now inherit from that base class and implement the necessary interface.

To include OpenGL primitives, we include the QtOpenGL header instead, which has all the platform-specific includes taken care of for us.

Added an exists() call beforehand.

Now all prerequisite packages should be listed for Arch, Fedora, and Ubuntu.

Updated some URLs, docs, and packages. Ubuntu and Arch instructions have not been verified on a live install, but the names come from their online package listings, so they should be correct.

No longer needed now that QSerialPort is in Qt5.1+

Onboard Files fixes

Debounce misconfiguration, fix onboard files view

FTP Unit Test fix

Mavlink File Transfer Protocol (FTP)

Changed FTP to tree view

Also added selection from tree view for downloading