geth: PKGBUILD with official release URL

PKGBUILD

# Maintainer: Afri 5chdn <aur@cach.co>
# Contributor: grimsock <lord.grimsock at gmail dot com>
# Contributor: Andy Weidenbaum <archbaum@gmail.com>
# Contributor: redfish <redfish at galactica pw>

pkgname=geth
pkgver=1.4.4
_commit="94ad694"
_timestamp_ARM="20160517130009"
_timestamp_Linux64="20160517160500"
pkgrel=1
pkgdesc="The go-ethereum commandline client (geth cli)."
arch=('x86_64' 'armv7h')
depends=(
  'gmp'
  'leveldb'
  'readline'
)
optdepends=('mist: Graphical Ethereum wallet and DApps browser.')
conflicts=(
  'geth-git'
  'go-ethereum'
  'go-ethereum-git'
)
provides=('geth')
url="https://github.com/ethereum/go-ethereum"
license=('GPL')

if [ ${CARCH} = "x86_64" ]
then
source=("${pkgname}-${pkgver}.tar.bz2::https://github.com/ethereum/go-ethereum/releases/download/v${pkgver}/geth-Linux64-${_timestamp_Linux64}-${pkgver}-${_commit}.tar.bz2")
sha256sums=('026e31452960b7fe6190431694e5062edbac1c9eed427c11c0f11e47123ff650')
_binpath=""
fi

if [ ${CARCH} = "armv7h" ]
then
source=( "${pkgname}-${pkgver}.tar.bz2::https://github.com/ethereum/go-ethereum/releases/download/v${pkgver}/geth-ARM-${_timestamp_ARM}-${pkgver}-${_commit}.tar.bz2")
sha256sums=('85e78db64bc0b81bf60d1eadc983841a97322b149a1b2c291fa720f9f1e22239')
_binpath="build/bin"
fi

source+=("https://raw.githubusercontent.com/ethereum/go-ethereum/master/COPYING")
sha256sums+=('48e234e35cf83b4f2543b0fbafcf7d33843378cc1a829654d5fc23f4e1b1e581')

package() {
  install -Dm755 "$srcdir/$_binpath/geth" "$pkgdir/usr/bin/geth"
  install -Dm644 "$srcdir/COPYING" "$pkgdir/usr/share/licenses/$pkgname/COPYING"
}