dict_load_table(): Initialize table->flags with zip_size.
mlog_parse_nbytes(), mlog_parse_string(): Add parameter page_zip and
write the changes also to the compressed page if one is specified.
Assert that these functions are not called on FIL_PAGE_INDEX pages.
buf_page_io_complete(): Replace block->frame with frame where appropriate.
recv_parse_or_apply_log_rec_body(): Add ut_a(!page_zip) where appropriate.
page_parse_delete_rec_list(): Add parameter page_zip.
This has not been extensively tested yet, because some other part of the
code breaks in "ibtestblob".
btr_free_page_low(): Add parameters "space" and "page_no", because they
are omitted from compressed BLOB pages.
btr0cur.c: Implement the compression and decompression of BLOB columns,
enabled at compile-time (#define ZIP_BLOB TRUE) for now.
btr_rec_free_externally_stored_fields(),
btr_copy_externally_stored_field(): Made static
mlog_log_string(): New function, split from mlog_write_string(), allows
to avoid a dummy memcpy() of compressed BLOB pages.
