temporary back to prebuilt libstelpcutils

it just for me, everybody might ignore this commit
Revert "temporary back to prebuilt libstelpcutils"

This reverts commit dbc79923c4c68dfb0e80b1d6e6e348aca951bb25.

Now everything is fine!
fixed exfat when building with >=GCC4.8

using prebuilt for now, but it should be fixed in sources