Revert recent changes to comphelper::OSequenceOutputStream

Some of the changes could be wrong and we don't need them.

This reverts commit 784d4bea86d8cbb3a855e557c465ce50a049cefc.
This reverts commit 8524d5aba59148eef94859289f00ab6477e0e821.
This reverts commit 018f1deae884febbbe639c7ee46b45ce4807e9d3.
This reverts commit 8124fddc5803b4e104d4fc2456cb92cb030d9436.

We use our own helper cache class in FastSaxSerializer
since f736eba5a9df8645849a37b08d2764a5f495ab45.

Change-Id: Iaca6b5b11cb32595db4420a02fa72b0007cf6286