Add the new structure of the iio-oscilloscope. Oscplot[ch] is the class that defines a "Capture" window.
iio_utils.h: Add an extra field(needed to associate data with the channel) to the iio_channel_info structure.
GUI almost complete. Improve the backend functionality. Fix bugs.
Time, Constellation and FFT are now working.
Merge branch 'master' into multi_plot_osc

Conflicts:
	Makefile
	osc.c
Make a "saveas" dialog for every capture window. Allow iio device selection in trigger dialog. Fix bug when displaying a constellation. Fix conflicts for osc.c and makefile. Change the scope of the current_device variable to osc.c only.
Reorganize the Transform class. Get rid of the memcpy functions used by the transforms.
Fix bug in impulse generator dialog. Opening the dialog the second time was causing the application to crash.
Create feature: every type of transform has its own settings dialog. Therefore multiple transform can have multiple sizes on the same plot or in different plots.
Merge branch 'master' into multi_plot_osc

Conflicts:
	osc.c
	osc.h
	plugins/fmcomms1.c
Fix major bug that was causing the application to crash.
Add the missing buffer_full variable.
trigger_dialog.c: Fix bug -  make frequency spin button inactive when no triggers are selected.
Makefile: Remove gthread2.0 duplicate.
oscplot.c: Fix all plots having the same grid.
oscplot.c: Fix bug that makes the application to crash when FFT and any other transform are running in the same time. rescale_databox() is the trouble maker, because it tries to rescale the FFT graph that is initialized with FLT_MAX value.
osc.c: Let osc.c know when to stop capturing data.
change horizontal scale label when FFT transform is displayed. Allow FFT transform from one device only in a plot.
Add the threading model that Robin added to the application on the master branch.
Handle plot destruction.