The pointer passing for display options is deprecated. This removes the
excess casting as the EDA_FRAME didn't need the base call with no value.
All requests for display options are now returned const and are updated
with a Set() routine after modification.
In Gerbview, this resolves an issue where the display options were not
stored because it was receiving the NULL from EDA_FRAME.
Moving pcbnew error strings that may be seen by the user to translated
strings. Strings that denote unexpected cases are moved to debug logs
as they are essentially asserts that should never be shown. The
exceptions are the messages shown when files are loaded. All unknown
items should show an error here.
Step 1 of the g_UserUnit global eradication. This commit includes
basic hookup of hotkeys, units tool-buttons and grid dialogs.
(cherry picked from commit e0500ab)