Improve dialog layout and fix UI policy issues with all of the dialog
boxes in the Gerbview and Pcbnew code paths.
Updated the use of component to footprint where appropriate.
This patch enables math expression evaluation for most of the text input
controls in pcbnew.
NEW: pcbnew text input controls are able to evaluate simple
mathematical expressions, including distance units (e.g. 5.0+(2*1.2mm)).
The file filter wild card was defined incorrectly causing the file picker
to not display *.stp and *.step file extensions. Change the wildcard per
wxFileDialog documentation.
Prevent the file extension from being forced to .stp even when the user
defined a different extension in the file picker.
Override TransferDataFromWindow to test for file existence and warn user
only once if a file overwrite can occur.
Minor STEP export dialog string and layout improvements.
Make kicad2step honor user's file extension rather than always setting it
to .stp.
Fixes lp:1709636
https://bugs.launchpad.net/kicad/+bug/1709636
Wayne Stambaugh
Maciej Suminski
jean-pierre charras
Cirilo Bernardo