Carray2blz

This is the result of the renaming of carray module to blz.  The changes basically boil down to:

carray (the module) -> blz
carray (the data container) -> barray
ctable (the data container) -> btable
cparams (the IO params) -> bparams

Some functionality from original carray package has been stripped off (some sorts of boolean selections, but they can be restored in the future, if needed).