MainWindow: Add shortcuts for the open/save menu items.
MainWindow: Add missing toolbar buttons.
SigSession: Fix typo in comment.
SamplingBar: Show total sampling time in a tooltip.
Put the time format function into a separate file.
SamplingBar: Use nicer time format in the tooltip.
Header: Invisible traces shouldn't influence the width.
Enabled C++11 build
Replaced lengthy iterator types with the auto keyword
Replaced BOOST_FOREACH with C++11 range-based for loops
Replaced boost::shared_ptr with std::shared_ptr
Replaced boost::thread/mutex etc. with std equivalents
Used a std::atomic for StoreSession::_units_stores and _unit_count
Replaced boost::function with std::function
Replaced boost::bind with C++11 lambdas
DeviceOptions::print_vdiv: Replace C-style string formatting with QString arg formatting
main: Use only the domain, not the whole URL.
MainWindow: Remember directory of last file that was opened/saved.
Use a separate widget to hold the cursor labels.

This way the cursor labels don't overlap with the ruler.
CursorHeader: Make the size dependend on the used font.