Minor adaptions to build script

(Portage version: 2.2.0_alpha188/cvs/Linux x86_64, signed Manifest commit with key EBE6A336BE19039C!)
version bump

(Portage version: 2.2.0_alpha188/cvs/Linux x86_64, signed Manifest commit with key E73C35B3)
Lowercase tar extension required for unpack, bug 476734.

(Portage version: 2.2.0_alpha188/cvs/Linux i686, signed Manifest commit with key 0xFDE8EF85AE5719A3)
Stable for ppc64, wrt bug #476296

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475788

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475794

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476438

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476184

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476556

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476178

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476702

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #453948

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475842

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475894

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #474312

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #476172

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475978

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #472910

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475744

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)
Stable for ppc64, wrt bug #475880

(Portage version: 2.1.12.2/cvs/Linux ppc64, RepoMan options: --include-arches="ppc64", signed Manifest commit with key 7194459F)