Merge branch 'maint'

Merge branch 'maint'

* maint:
  Fixed setting of USB_LIBS for *win*
  Fix so that non-Darwin OSs use USB_LIBS correctly for linking
  New way of checking for various LIBUSB names; for legacy version, make sure the symbol 'usb_debug' exists (so-as to not use the 'compat' version).
  Finally, the simple fix for the qtgui issues; also, changed the naming scheme output from _moc to .moc files because I think this looks cleaner.
  Removing Waterfall3DPlot. The qwt_plot3d is too much of a hassle to deal with and the plotting is not that stable even when it does work. This does not change the API.
  Fixed gitignore to reflect changes in moc/ui file naming.
  Fixes a lot of warnings by cleaning up namespace issues.
  Finally, the simple fix for the qtgui issues; also, changed the naming scheme output from _moc to .moc files because I think this looks cleaner.
  Removing qwtplot3d dependency and fixing a missed include in waterfallGlobalData.h.
  Removing Waterfall3DPlot. The qwt_plot3d is too much of a hassle to deal with and the plotting is not that stable even when it does work. This does not change the API.