add git and golang for windows, fix some PATH stuff

git/install.ps1

@@ -0,0 +1,56 @@
+#!/usr/bin/env pwsh
+
+$pkg_cmd_name = "git"
+$pkg_download = "$Env:USERPROFILE\Downloads\$Env:WEBI_PKG_FILE"
+
+$pkg_src = "$Env:USERPROFILE\.local\opt\$pkg_cmd_name-v$Env:WEBI_VERSION"
+
+$pkg_dst = "$Env:USERPROFILE\.local\opt\$pkg_cmd_name"
+$pkg_dst_cmd = "$pkg_dst\cmd\$pkg_cmd_name"
+$pkg_dst_bin = "$pkg_dst\cmd"
+
+# Fetch archive
+IF (!(Test-Path -Path "$pkg_download"))
+{
+    # TODO: arch detection
+    echo "Downloading $Env:PKG_NAME from $Env:WEBI_PKG_URL to $pkg_download"
+    & curl.exe -A "$Env:WEBI_UA" -fsSL "$Env:WEBI_PKG_URL" -o "$pkg_download.part"
+    & move "$pkg_download.part" "$pkg_download"
+}
+
+IF (!(Test-Path -Path "$pkg_src"))
+{
+    echo "Installing $pkg_cmd_name"
+    # TODO: temp directory
+
+    # Enter opt
+    ($none = pushd .local\tmp) | out-null
+
+        # Remove any leftover tmp cruft
+        Remove-Item -Path "$pkg_cmd_name*" -Recurse -ErrorAction Ignore
+
+        # Unpack archive
+        # Windows BSD-tar handles zip. Imagine that.
+        echo "Unpacking $pkg_download"
+        IF (!(Test-Path -Path "$pkg_cmd_name-v$Env:WEBI_VERSION")) {
+            New-Item -Path "$pkg_cmd_name-v$Env:WEBI_VERSION" -ItemType Directory
+        }
+        ($none = pushd "$pkg_cmd_name-v$Env:WEBI_VERSION")  | out-null
+            & tar xf "$pkg_download"
+        ($none = popd)  | out-null
+
+        # Settle unpacked archive into place
+        echo "New Name: $pkg_cmd_name-v$Env:WEBI_VERSION"
+        echo "New Location: $pkg_src"
+        Move-Item -Path "$pkg_cmd_name-v$Env:WEBI_VERSION" -Destination "$Env:USERPROFILE\.local\opt"
+
+    # Exit tmp
+    $none = popd
+}
+
+echo "Copying into '$pkg_dst' from '$pkg_src'"
+Remove-Item -Path "$pkg_dst" -Recurse -ErrorAction Ignore
+Copy-Item -Path "$pkg_src" -Destination "$pkg_dst" -Recurse
+
+# Add to path
+& "$Env:USERPROFILE\.local\bin\pathman.exe" add %USERPROFILE%\.local\opt\git\cmd