Factor out save current canvas view to image file code from symbol editor
code so it can be used anywhere.
Add ability to save to any image format supported by wxBitmapType. See
https://docs.wxwidgets.org/3.0/gdicmn_8h.html#a90a1eb6d85b5044a99b706fd979f27f5.
Currently only PNG output is implemented.
Please note that there is a minor bug that appears to be due to the
scroll bars which causes unfilled areas on the right and bottom edges
of the image. This always existed in the save symbol editor view
image but it was not as noticeable because by default the background
color is white. It is very noticeable in the footprint editor with
a black background.
The usual smattering of coding policy and comment fixes.
Fixes lp:1802127
https://bugs.launchpad.net/kicad/+bug/1802127
This is meant as a stopgap for 5.0, with plans to add proper scaled
icons in the 6.0 cycle. A function KiScaledBitmap() is added, which
works like KiBitmap() except it scales the bitmap according to the
calling window's font size. Controls have been added to all the main
applications to let the user select scaling manually (these were omitted
from smaller apps that didn't already have a place to put them).
In addition, in eeschema only, the pixel height of the system font is
shown in the options dialog for diagnostics. This is only for collecting
feedback before 5.0 release from users with different displays and will
be removed.
* Correct all user strings and comments for the correct capitalization of
application names according to JP. They are KiCad, Pcbnew, CvPcb,
Eeschema, and GerbView.
* Add a note the the user interface policy about the correct capitalization.