Add SVG support to ImageMagick

[cabarnes]

Compiles ImageMagick with SVG support

[btimby]

The debian package uses the following flags:

        --enable-reproducible-build \
        --prefix=/usr \
        --libdir=/usr/lib/$(DEB_HOST_MULTIARCH) \
        --docdir=/$(DOC_PKG_PATH) \
        --with-extra-doc-dir=' (on debian system you may install the imagemagick-$(IMVERSION) package)' \
        --sysconfdir=/etc \
        --with-includearch-dir=/usr/include/$(DEB_HOST_MULTIARCH)/ \
        --mandir=/usr/share/man \
        --infodir=/usr/share/info \
        --with-modules \
        --with-gs-font-dir=/usr/share/fonts/type1/gsfonts \
        --with-magick-plus-plus \
        --with-djvu \
        --with-heic \
        --with-openjp2 \
        --with-webp \
        --with-wmf \
        --without-gvc \
        --enable-shared \
        --without-dps \
        --without-fpx \
        --with-perl \
        --with-perl-options='INSTALLDIRS=vendor' \
        --x-includes=/usr/include/X11 \
        --x-libraries=/usr/lib/X11 \
        --without-rsvg

NOTE: I need to look up the values of the variables above...