<rdar://problem/12953018>

Synthetic children and summary for std::vector<bool> (for both libcxx and libstdcpp).
std::vector<bool> is a special case and is custom-implemented to be a vector of bits, which means we failed to handle it with the standard std::vector<T> formatter.
This checkin provides custom formatters that work correctly



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@174333 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the m_images(NULL) hack in the Target ctor now
that the original issue has been fixed by r174222.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@174334 91177308-0d34-0410-b5e6-96231b3b80d8