Add gcc-4.7-base to ubuntu-precise; resolves travis-ci/apt-package-whitelist#2523
Add gcc-4.7-base to ubuntu-precise; resolves travis-ci/apt-package-whitelist#2523

Packages: gcc-4.7-base libgcc-4.7-dev lib64gcc-4.7-dev lib32gcc-4.7-dev libhfgcc-4.7-dev libsfgcc-4.7-dev libn32gcc-4.7-dev gcc-4.7 gcc-4.7-multilib gcc-4.7-plugin-dev gcc-4.7-hppa64 gcc-4.7-spu g++-4.7-spu gfortran-4.7-spu cpp-4.7 cpp-4.7-doc gcc-4.7-locales g++-4.7 g++-4.7-multilib libmudflap0-4.7-dev gobjc++-4.7 gobjc++-4.7-multilib gobjc-4.7 gobjc-4.7-multilib libobjc-4.7-dev lib64objc-4.7-dev lib32objc-4.7-dev libn32objc-4.7-dev libhfobjc-4.7-dev libsfobjc-4.7-dev gfortran-4.7 gfortran-4.7-multilib gfortran-4.7-doc libgfortran-4.7-dev lib64gfortran-4.7-dev lib32gfortran-4.7-dev libn32gfortran-4.7-dev libhfgfortran-4.7-dev libsfgfortran-4.7-dev gccgo-4.7 gccgo-4.7-multilib gccgo-4.7-doc libgo0 libgo0-dbg lib64go0 lib64go0-dbg lib32go0 lib32go0-dbg libn32go0 libn32go0-dbg libstdc++6-4.7-dev libstdc++6-4.7-pic libstdc++6-4.7-dbg lib32stdc++6-4.7-dev lib32stdc++6-4.7-dbg lib64stdc++6-4.7-dev lib64stdc++6-4.7-dbg libn32stdc++6-4.7-dev libn32stdc++6-4.7-dbg libhfstdc++6-4.7-dev libhfstdc++6-4.7-dbg libsfstdc++6-4.7-dev libsfstdc++6-4.7-dbg libstdc++6-4.7-doc gcc-4.7-soft-float gcc-4.7-doc gcc-4.7-source

travis-ci/apt-package-whitelist,travis-ci/apt-package-whitelist