gitian: Build OpenSSL and Boost dependencies for linux

After these changes, openssl and boost are built statically in the linux build and use the same versions as the win32 build.

`elfread -d` now reports

bitcoind:

    0x00000001 (NEEDED)                     Shared library: [librt.so.1]
    0x00000001 (NEEDED)                     Shared library: [libstdc++.so.6]
    0x00000001 (NEEDED)                     Shared library: [libm.so.6]
    0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
    0x00000001 (NEEDED)                     Shared library: [libpthread.so.0]
    0x00000001 (NEEDED)                     Shared library: [libc.so.6]

bitcoin-qt:

    0x00000001 (NEEDED)                     Shared library: [librt.so.1]
    0x00000001 (NEEDED)                     Shared library: [libQtGui.so.4]
    0x00000001 (NEEDED)                     Shared library: [libQtNetwork.so.4]
    0x00000001 (NEEDED)                     Shared library: [libQtCore.so.4]
    0x00000001 (NEEDED)                     Shared library: [libQtDBus.so.4]
    0x00000001 (NEEDED)                     Shared library: [libpthread.so.0]
    0x00000001 (NEEDED)                     Shared library: [libstdc++.so.6]
    0x00000001 (NEEDED)                     Shared library: [libm.so.6]
    0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
    0x00000001 (NEEDED)                     Shared library: [libc.so.6]