- Set the modified flag even for null segment removal

remove a static wxString constructor which was out of sequence with another dependent one, at least with one toolchain.

Key events are handled by wxEVT_CHAR instead of wxEVT_KEY_[UP|DOWN]. Fixed issue of chars that require modifiers (e.g. ? is Shift+/ on US keyboard layout).

Hot keys specific to a tool have priority over global hot keys (TOOL_ACTION scope: AS_GLOBAL/AS_CONTEXT is finally handled properly).

was used locally.  Then comment it out in favor of a newer strategy for
filling in nicknames in cvpcb. 

Add MODULE* FootprintLoadWithOptionalNickname( const FPID& aFootprintId )
        throw( IO_ERROR, PARSE_ERROR );
from code found elsewhere.

Board is cached in GAL only when the canvas is activated.

Items that may be modified using EDIT_POINTs used to stay selected after pressing ESC (only EDIT_POINTs got away) - fixed.

Edit->Global Deletions & Edit->Cleanup Tracks and Vias work in GAL, without toggling between canvases.