Add changes file for 4.2

Change-Id: I56f97306de5d3280ade60cc335b55c2e79f89bad
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

dist/changes-4.2.0.md

+Qt Creator version 4.2 contains bug fixes and new features.
+
+The most important changes are listed in this document. For a complete
+list of changes, see the Git log for the Qt Creator sources that
+you can check out from the public Git repository. For example:
+
+    git clone git://code.qt.io/qt-creator/qt-creator.git
+    git log --cherry-pick --pretty=oneline origin/4.1..v4.2.0
+
+General
+
+* Added experimental editor for Qt SCXML
+* Added pattern substitution for variable expansion
+  `%{variable/pattern/replacement}` (and `%{variable//pattern/replacement}`
+  for replacing multiple matches)
+* Added default values for variable expansion (`%{variable:-default}`)
+* Added Help > System Information for bug reporting purposes
+  (QTCREATORBUG-16135)
+* Added option to hide the central widget in Debug mode
+
+Welcome
+
+* Added keyboard shortcuts for opening recent sessions and projects
+* Improved performance when many sessions are shown
+
+Editing
+
+* Added action for selecting word under cursor (QTCREATORBUG-641)
+* Fixed highlighting of Markdown files
+  (QTCREATORBUG-16304)
+
+Help
+
+* Added option to open link and current page in window (QTCREATORBUG-16842)
+
+All Projects
+
+* Reworked Projects mode UI
+* Grouped all device options into one options category
+* Added support for toolchains for different languages (currently C and C++)
+
+QMake Projects
+
+* Removed Qt Labs Controls wizard which is superseded by Qt Quick Controls 2
+* Fixed `Open with Designer` and `Open with Linguist` for mobile and embedded Qt
+  (QTCREATORBUG-16558)
+* Fixed Add Library wizard when selecting library from absolute path or
+  different drive (QTCREATORBUG-8413, QTCREATORBUG-15732, QTCREATORBUG-16688)
+
+CMake Projects
+
+* Added support for CMake specific snippets
+* Added support for platforms and toolsets
+* Added warning for unsupported CMake versions
+* Added drop down for selecting predefined values for properties
+* Improved performance of opening project (QTCREATORBUG-16930)
+* Made it possible to select CMake application on macOS
+* Fixed that all unknown build target types were mapped to `ExecutableType`
+
+Qbs Projects
+
+* Made generated files available in project tree (QTCREATORBUG-15978)
+
+C++ Support
+
+* Added preview of images to tool tip on Qt resource URLs
+* Added option to skip big files when indexing (QTCREATORBUG-16712)
+* Added notification for parsing errors in headers
+* Fixed `Move Definition to Class` for functions in template class and
+  template member functions (QTCREATORBUG-14354)
+* Fixed issues with `Add Declaration`, `Add Definition`, and
+  `Move Definition Outside Class` for template functions
+* Clang Code Model
+    * Improved responsiveness of completion and highlighting
+
+Debugging
+
+* Added pretty printing of `QRegExp` captures
+* Added pretty printing of `QStaticStringData`
+* Improved pretty printing of QV4 types
+* Made display of maps more compact
+* Fixed pretty printing of `QFixed`
+* LLDB
+    * Added support for Qt Creator variables `%{...}` in startup commands
+
+QML Profiler
+
+* Added option to show memory usage and allocations as flame graph
+* Added option to show vertical orientation lines in timeline
+  (click the time ruler)
+
+Qt Quick Designer
+
+* Added completion expression editor
+* Added menu for editing `when` condition of states
+* Added editor for managing C++ backend objects
+* Added reformatting of `.ui.qml` files on save
+* Added support for exporting single properties
+* Added support for padding (Qt Quick 2.6)
+* Added support for elide and various font properties to text items
+* Fixed that it was not possible to give extracted components
+  the file extension `.ui.qml`
+* Fixed that switching from Qt Quick Designer failed to commit pending changes
+  (QTCREATORBUG-14830)
+* Fixed issues with pressing escape
+
+Diff Viewer
+
+* Added local diff for modified files in Qt Creator (`Diff` >
+  `Diff Current File`, `Diff` > `Diff All Modified Files`)
+  (QTCREATORBUG-9732)
+* Fixed that reload prompt was shown when reverting change
+
+Version Control Systems
+
+* Gerrit
+    * Fixed pushing to Gerrit when remote repository is empty
+      (QTCREATORBUG-16780)
+
+Test Integration
+
+* Added option to disable crash handler when debugging
+* Fixed that results were not shown when debugging (QTCREATORBUG-16693)
+* Fixed that progress indicator sometimes did not stop
+
+Model Editor
+
+* Added zooming
+* Added synchronization of selected diagram in diagram browser
+
+Platform Specific
+
+Android
+
+* Improved stability of determination if application is running
+* Fixed that running without deployment did not start emulator
+  (QTCREATORBUG-10237)
+* Fixed that permission model downgrade was not detected as error
+  (QTCREATORBUG-16630)
+* Fixed handling of minimum required API level (QTCREATORBUG-16740)
+
+Credits for these changes go to: