update .gitignore
editor: use QKeySequence::StandardKey

Each target-platform has it's own set of default key-bindings. Use
QKeySequence::StandardKey to get the OS-default behaviour.
editor: use icons from theme, if available
editor: use Qt's built-in window-title management

This allows each platform to get the title styled in it's
traditional way.

Unfortunately, we also need to work around QTBUG-16507 for this
to work properly.
editor: handle palette-changes
editor: handle font-changes the same way as palette-changes
Merge branch 'update-gitignore'
licensing: remove copyright statements from code

Keeping these up-to-date is a pain, and it's strictly speaking not
required. So let's just drop it, the git repository contains much
more accurate author-information.
licensing: do not track contributors

Tracking indevidual contributors in the source-code is a fool's
errand, and the code-repository already does this much more
accurately.

Replace individual names with "Contributors" to avoid having to
keep track. We were already missing alot of people anyway.
Merge branch 'master' into editor-structs

Conflicts:
	lib/data.c
	lib/data.h
editor: rename TrackView to TrackArea