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.
2) Change from legacy Cu stack to counting down from top=(F_Cu or 0).
The old Cu stack required knowing the count of Cu layers to make
sense of the layer number when converting to many exported file types.
The new Cu stack is more commonly used, although ours still gives
B_Cu a fixed number.
3) Introduce class LSET and enum LAYER_ID.
4) Change *.kicad_pcb file format version to 4 from 3.
5) Change fixed names Inner1_Cu-Inner14_Cu to In1_Cu-In30_Cu and their
meanings are typically flipped.
6) Moved the #define LAYER_N_* stuff into legacy_plugin.cpp where they
can die a quiet death, and switch to enum LAYER_ID symbols throughout.
7) Removed the LEGACY_PLUGIN::Save() and FootprintSave() functions.
You will need to convert to the format immediately, *.kicad_pcb and
*.kicad_mod (=pretty) since legacy format was never going to know
about 32 Cu layers and additional technical layers and the reversed Cu
stack.
File "rules" has instructional text as comments near top.
2) Convert all text files in repo to LF line ending form.
Any checkout done with "rules" in play will convert the working
tree to native line ending, while keeping repo as LF line ending.
SVG export does not use no more wxWidgets wxDC.
In pcbnew SVG files can be created by plot menu (in B&W) or export SVG menu (B&W or Color).
Export SVG menu is more suitable to create a view of a board, and plot menu is better to create a B&W document of silkscreen layers.
(In the future, the 2 menus could be merged, because they are not very different).
Note: pcbnew plot code is cleaned, mainly in dialog files, but still needs more cleanup.