extending drcontainer

_From [zhao...@google.com](https://code.google.com/u/106321947286816917100/) on August 27, 2012 12:26:47_

There are a few features that good to have but drvector did not deliver:
1. allocate memory from a) fixed address or b) above-2G address in 64-bit
2. allocate memory actual data instead of pointers pointing to the data.
3. non-moved memory address, i.e. the pointer can be returned to client directly
4. thread-private and global data.

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=885_