rtems-tools: coverage covoar GSoC merge

[Chris Johns]

Hi,

This patch is the covoar work from GSOC that I have simplied so symbol loading
from the component libraries is managed by an INI file that defines the symbol
set that is directly loaded from the archive ELF files in the archive by the RLD
toolkit code.

I detect the build target and BSP from the test executable's path as the
test and the libraries need to match. This dependence is important and needed.

Some of the rtems-test support that was in the orignal patches has been reworked
but it needs other changes I do not have for me to test.

Finally, covoar needs to be fix before we do anything else. It is exec'ing shell
commands with redirects, pipes and embeddied command like `dos2unix` which
cannot stay. There is no dos2unix command in a standard FreeBSD install and
this means I cannot run covoar. All exec calls need to be review and cleaned up.

Chris