Make sure KiCad updates from upstream every build.

[adamwolf]

Fix wxwidgets configuring and updating every build.

I've made a bunch of changes from some investigations prompted by nickoe.

KiCad will now update when you build, and it will apply the KiCad patches on the top.

You can see it in the terminal like this:

[ 79%] Performing update step for 'kicad' cd /Users/wolf/wnl/kicad/kicad-mac-builder/build/kicad/src/kicad && git fetch cd /Users/wolf/wnl/kicad/kicad-mac-builder/build/kicad/src/kicad && echo "Making sure we aren't in the middle of a crashed git-am" Making sure we aren't in the middle of a crashed git-am cd /Users/wolf/wnl/kicad/kicad-mac-builder/build/kicad/src/kicad && git am --abort || true cd /Users/wolf/wnl/kicad/kicad-mac-builder/build/kicad/src/kicad && git reset --hard origin/master HEAD is now at b0b5d9139 pcbnew: fix OpenMP synch issue cd /Users/wolf/wnl/kicad/kicad-mac-builder/build/kicad/src/kicad && /Users/wolf/wnl/kicad/kicad-mac-builder/kicad-mac-builder/bin/git-multipatch.sh "/Users/wolf/wnl/kicad/kicad-mac-builder/kicad-mac-builder/patches/kicad/*.patch" /Users/wolf/wnl/kicad/kicad-mac-builder/kicad-mac-builder/patches/kicad/0001-Setup-PYTHON_FRAMEWORK-embedded-in-MacOS.patch Applying: Setup PYTHON_FRAMEWORK embedded in MacOS. /Users/wolf/wnl/kicad/kicad-mac-builder/kicad-mac-builder/patches/kicad/2-0001-Backported-BundleUtilities-and-GetPrerequisites-from.patch Applying: Backported BundleUtilities and GetPrerequisites from Cmake 3.11.1 to let macOS packaging work at least back to 3.6.2. /Users/wolf/wnl/kicad/kicad-mac-builder/kicad-mac-builder/patches/kicad/3-0001-Fixup-ngspice-library-when-bundling-on-macOS.patch Applying: Fixup ngspice library when bundling on macOS. [ 81%] Performing configure step for 'kicad'

I also set wxwidgets not to update.

Fixes #48. Fixes #161. Fixes #162.