Refactor PKGBUILD - Fix #3

• Fix #3
• Use origin source tarball for packaging
• Use now the needed library from this tarball
• Add upstream README*.md files to the doc folder
• remove redundant dependancy grep (is already a dependency of the base package)
• remove superfluous string quotes
  (almost all variables, up to ${pkgdir} and ${srcdir}, must not contain whitespaces anyway)