qtgui: a few more fixes for qwt 5.2/6.0.
qtgui: more compatability issues.
qtgui: wip: working to make plots backwards compatible with qwt 5.2.
qtgui: adjusting intensity knobs and auto scale in waterfall works in qwt6.
qtgui: fixed waterfall color map issue under qwt6.
qtgui: waterfall plot mostly working under qwt6 (plots, but updates to scale and color not working yet).
qtgui: wip: updating qtgui to work with QWT 6 (and trying to maintain backwards compatability to 5.2). This wip works for just the fft plots.
added high_res_timer_epoch to give ticks at the epoch
qtgui: make a common function for the time label creation in waterfall
qtgui: removed all traces of highResTimeFunctions.h
qtgui: removed most of the functions in highResTimeFunctions.h
qtgui: partially switch to gruel high res timer
qtgui: replace timespec with typedef so its easier to replace
gr-qtgui: adding copyright dates to qtgui files.
gr-qtgui: adding double-click point selector to main gui widgets.
gr-qtgui: fixed some signed/unsigned comparison warnings.
gr-qtgui: restructuring qtgui directory to new layout.