Various: new commands and buffer management

* Change default buffer to 4096
* New commands: Read, send signal, terminate and write
* Background console now change to privileged when foreground console is
or change to privileged
* Fix cancel asynchronous programs launched on privileged consoles
(non-privileged background console is not able to kill or signal)
* Fix root directory default
* Allow send signal and terminate, in addition to cancel, for
AsyncResultExecutable programs
* Passing console trace status to commands (allow programs to use user
preference)
* Allow to programs to access the stdout to respond to programs (xe:
write to stdin of dd).
* Fix ResolveLinkCommand when src is the root directory
* Remove check of error code in checkStdErr of the shell. Determine the
errors based on the returned text. Error code is not necessary because
the check is over stderr, not stdin.
* Create separate methods for create privileged console (one with no
check and other for check and change to non-privileged on error)
* Fix detection of start of program on Shell
* No send string controls to asynchronous programs on parsePartial
method
(cut
buffers prior to invoke)
* Create static method on Permissions to load from raw and octals
strings.
* Fix disk usage and mount point info when no background console is
available
* Fix test app name. Changed to CMExplorerTest
* Fix exec test, once there are a write command. Now write the shell
program and execute to check results.