Reuse 4.2.4 (20060511)
======================
Added support for special Linux kernel capabilities for secure
execution (CAP_SYS_OPERATIONS). The capabilities are detected at
configure time and their support is enabled.

(exec.c) new functions:
  task_EnableSecureExec
  task_SetQuietFlag
  task_GetErrorMessage

`task_EnableSecureExec' sets the "secure execution" flag. If this
flag is set, the CAP_SYS_OPERATIONS capability is dropped before
execing a program. This works only for statically linked programs,
though.

`task_SetQuietFlag' sets the "quiet" flag. If it is set, no error
messages are printed to the stderr, instead they are saved and
are available by `task_GetErrorMessage' function.

`task_GetErrorMessage' retrieves the latest error message.