Improved performance and reduced memory footprint of schema validation involving large maxOccurs:

- the CMStateSet uses a sparsely allocated matrix to store the bits, resulting in less memory usage and faster bitwise operations (when analyzing an unallocated chunk, no operations are done); also, having moved the dynamic buffer data members into a separate structure, the space used by two pointers has been added to the cached bit fields, that is now 128 bits
- the DFA builder chooses the faster algorithm depending on the data being analyzed.
The regression test for XERCESC-1051 now completes in 30 seconds instead of 80

git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@807213 13f79535-47bb-0310-9956-ffa450edef68