* This patch adds rebuildEM tool support to work with compressed files.
* This patch increases a version of the file header.
Note: Default version of the `rebuildEM` tool was using very old API,
those functions are not present currently. So `rebuildEM` will not work with
files created without compression, because we cannot deduce some info which are
needed to create column extent.
* This patch extends CompressedDBFileHeader struct with new fields:
`fColumWidth`, `fColDataType`, which are necessary to rebuild extent map
from the given file. Note: new fields do not change the memory
layout of the struct, because the size is calculated as
max(sizeof(CompressedDBFileHeader), HDR_BUF_LEN)).
* This patch changes API of some functions, by adding new function
argument `colDataType` when needed, to be able to call `initHdr`
function with colDataType value.
