seemingly working pkgbuild for gimp-gap

pkgname=gimp-gap
pkgver=2.6.0
pkgrel=5.1
pkgdesc="Gimp Animation Package, gimp's plugin for animation"
url="https://www.gimp.org/tutorials/Using_GAP/"
arch=('x86_64' 'i686')
license=('GPLv3')
depends=('gimp>=2.6.0' 'glib2')
makedepends=('intltool')
optdepends=('xvidcore: compression codec'
			'lbzip2: data compressor'
			'faac: audio encoder'
			'faad2: audio decoder'
			'lame: mpeg layer 3 codec'
			'libx264: H264 codec')
source=("http://download.gimp.org/pub/gimp/plug-ins/v2.6/gap/${pkgname}-${pkgver}.tar.bz2")
md5sums=('249ed829de8b78675c0fe4ef4212089f')

# I have to admit I don't fully understand this stuff
build() {
  cd "${srcdir}/${pkgname}-${pkgver}"

# I don't know why, but I found it in a prior PKGBUILD
  sed -i 's:AM_CONFIG_HEADER:AC_CONFIG_HEADERS:' configure.in
  sed -i 's:AM_PROG_CC_STDC:AC_PROG_CC:' configure.in

# -lm must be one of the last libraries for the compilation to succeed
  sed -i 's/-lm"/"/' configure

  ./configure \
    --prefix=/usr \
    --exec-prefix=/usr \
    --sbindir=/usr/bin \
    --sysconfdir=/etc \
    --localstatedir=/var \
    --libdir=/usr/lib \
    --includedir=/usr/include \
    --datadir=/usr/share \
    --disable-libmpeg3

# libmpeg3 seems to goof up for a lot of people so it's disabled

# Add -lm as the last library to be linked and start compiling
  make LIBS+=' -lm'
}

package() {
  cd "${srcdir}/${pkgname}-${pkgver}"

  make DESTDIR="${pkgdir}" install
}