[Qt-creator] Feedback on 4.2

[Georger Araujo]

Hi,
I have just updated to 4.2 and so far I like it. I have some bits of feedback:

- When I opened a (non-Qt) C++ project, "#include <iostream>" was underlined
and the error tooltip read "iostream: No such file or directory". While the
project still built fine, it was annoying. I found the root cause: the C++
compiler was auto-detected as "<No compiler>" on both my MSVC2013 and MSVC2015
5.6.2 32-bit kits; curious, since the C compiler was auto-detected correctly.
After I manually set both to the same as the C compiler, the #include no
longer showed the error.

- How about assigning a keyboard shortcut to Show Mode Selector (the
associated command is "ToggleModeSelector")? I use and suggest F12.
Together with hiding the Sidebar (Alt+0), it's really handy for freeing up
screen space when working on two files side by side.

- The color of the "Auto Complete" element in the Modnokai Night Shift v2
color scheme makes the text mostly unreadable (that element was not part of
the scheme when I contributed it back in June [1]). I suggest changing it.
I tried many different colors and #2f4f4f looked decent.

[1] https://codereview.qt-project.org/#/c/162866/

Best regards,

Georger