1. Additional locations of GNU tools in Solaris; there two directories
where GNU tools might be found In Solaris. These should be searched too.
2. Standard tail(1) command in Solaris does not have -n option; for
returning last line, it should call as tail -1 instead of tail -n1
3. The usage of which tool is changed to use absolute path to be consistent
with verification of its presence.
Closes patch 2507800.
Credits go to Sergio Gutierrez