Most users of bind contexts don't use bound objects or object params, so 
don't create an initial table. Instead, create it on demand and use an 
exponential algorithm for increasing the size of the table when full.

Spotted by Ron Yorston.

Thanks to Dmitry Timoshkov for a test case.

Added separate parent and child header controls for each test case and
fixed a typo ('Data Modified' should be 'Date Modified').

rpcrt4: Tests that show that the allocation rules for unmarshaling a conformant array are the same as those for a simple structure.