Add NSIS file for use with cross-compiled PulseView.
Replace GPLv2+ references with GPLv3+.

Most of the PulseView files may be licensed under the GPLv2+, but by linking
against libsigrok (which is GPLv3+) the binary as a whole is GPLv3+.

Reflect that in the COPYING file, the documentation, and the GUI.
win32: Use -mwindows to avoid opening a "DOS box".
Bring the cursors into view when they are shown
Added an accelerator for show/hide cursors
Made the sdi a persisent property of SigSession
Only the open the file if the user clicked ok in the dialog
Update the SigSession device, when it is selected by the user
Open/close devices as needed
Hardcode maximum supported probes to 64 for now

SR_MAX_NUM_PROBES disappeared from libsigrok.h, along with that
limitation.
Added missing virtual destructors

This fixes bug #106.
Fix "Failed to configure samplerate." warnings.

We need to keep the sample rate selectors hidden until they have been
reconfigured and we need to ignore the samplerate when the device
selector is hidden.

This fixes bug #109.
Added DeviceManager

This class now manages the application device list, scanning for
devices, and releasing them when they are no longer needed.

This fixes bug #108.
Factored device title printing code out into pv::DeviceManager::format_device_title

This fixes the earlier bug where pv::DeviceManager::compare_devices
would crash if any of the device string fields were NULL.
manpage: Various fixes and updates.
Added assertions to confirm that the session was terminated cleanly
Set the title of the main toolbar
Make labels an even height

This prevents some of the blurring effects to the label outline
that can be seen when the outline falls over a half-pixel.
pv::DeviceManager now manages opening/closing devices

It also notifies pv::SigSession objects when their devices are
going to be cleared.
Stop capture before connecting to a device