Allows parameter access from QML among other things

And I really mean it this time!

Copy platforms plugins to install

Revised the DLLs that are copied post-compilation so that QGC.exe can run.
Improved robustness by quoting all filenames/paths.

Files were not being copied to correct location

Files were not being copied to correct location

Either this location is incorrect, or it is an optional install that I
haven’t figured out how to get yet. Either way, this is failing
TeamCity Windows Releases builds which I want to turn on. So for now,
I’m disabling. I’ll figure out how to make it work correctly with my
work on generating windows installs.

Either this location is incorrect, or it is an optional install that I
haven’t figured out how to get yet. Either way, this is failing
TeamCity Windows Releases builds which I want to turn on. So for now,
I’m disabling. I’ll figure out how to make it work correctly with my
work on generating windows installs.

Also fixed a number of other release build problems

Still not working fully but more information is getting in there than
before. Also by removing VERSION from .pro it fixes problem with vs
proj being built incorrectly.

Made them more understandable for what is needed and for why. Removed
duplication and made sure builds used common settings across all OS
flavors. Removed mingw support for Windows since it was only partially
implemented.