User configurable sim plot colors

[Ian McInerney]

It would be good to add the ability for the user to define arbitrary colors, and also to add as many as they wish to the simulator window (currently there are 16 hard-coded colors in the simulator window).

This could be worked into a color preferences profile with lp:1847270.

(note that there was a recent bug report that increased the available colors to 16 and added better deconfliction when assinging colors, lp:1851372, but this extends that).

Application: Eeschema
Version: (5.99.0-349-gfa14d5b9f-dirty), debug build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.65.3 OpenSSL/1.1.1c-fips zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.20.2 (+libidn2/2.0.5) libssh/0.9.0/openssl/zlib nghttp2/1.38.0
Platform: Linux 5.1.18-300.fc30.x86_64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    Build date: Nov 7 2019 16:43:32
    wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
    Boost: 1.69.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.65.3
    Compiler: Clang 8.0.0 with C++ ABI 1002

Build settings:
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_PYTHON3=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON
    KICAD_STDLIB_DEBUG=OFF
    KICAD_STDLIB_LIGHT_DEBUG=ON
    KICAD_SANITIZE=ON

[KiCad Janitor (kicad-janitor)]

KiCad bug tracker has moved to Gitlab. This report is now available here: https://gitlab.com/kicad/code/kicad/-/issues/2536