base: Add support for newer versions of IPython
base: Add support for newer versions of IPython

IPython is used for the interactive gem5 shell if it exists. IPython
made API changes in version 0.11. This patch adds support for IPython
version 0.11 and above.

haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,haowu4682/gem5,LingxiaoJIA/gem5,haowu4682/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,LingxiaoJIA/gem5,haowu4682/gem5,haowu4682/gem5,LingxiaoJIA/gem5