Some fixes to allow non libtool building on AIX.
Rebuild configure.
Fix a integer overflow in btape.

From now on you can use blocksize bigger then 230 Kb in btape as
it caculates the max-file-size as 10000 (number of records) times
the device blocksize but that will overflow a 32 bits integer so
explicitly cast it to 64 bits.
Store sizes as unsigned.

All conversion and printing functions already assume handling an
unsigned but the type is still signed. A negative size of course makes
no sense. The only thing we are interested in is if its zero or more
(e.g. zero means not set so ignore the setting.) but a zero also fits in
an unsigned variable.
Fix compile problems when compiling without libz support.

Don't depend on Bytef as datatype which is a libz invention.
Merge branch 'master' of https://github.com/bareos/bareos