BLOB pointers, trx_id, and roll_ptr.

btr_empty(), btr_create(), page_create(): Add parameter "index", as some
index information will be encoded on the compressed page.

Define REC_NODE_PTR_SIZE as 4.

Allow btr_page_reorganize() and btr_page_reorganize_low() to fail.

Define the error code DB_ZIP_OVERFLOW.

Make row_ins_index_entry_low() static.

page0zip: Encode the index, log reorganized records, and store uncompressed
fields separately from the compressed data stream.