PulseView now has session setup save/restore support

PulseView recently gained initial support for a feature that has been requested quite a bit in the past: saving and restoring a specific session setup.

There was support for restoring (most of) the state from the last PulseView run already; it would re-open your last-used *.sr file, the decoders that were used, and so on.

However, in the current nightly builds you can now also save a specific session to a new file type with the .pvs extension, and restore settings from that file at a later point in time.

For example, if you're working with a foo.sr file and a bar.sr file, different settings and decoders in each, you can now also save a foo.pvs and/or bar.pvs file, and restore those specific session setups a few weeks later, without having to remember the exact setup, without having to click a whole bunch of times to restore all decoders and so on...

Feedback (e.g. on IRC, #sigrok on Freenode) and bug reports for this feature are welcome, as always.