Change default SharedArea

Relative directories cannot work. Assume $HOME instead.

Needs checking/testing as even if it should work, not guaranteed.
Merge pull request #1921 from sposs/fixSSHCE

!!! [v6r10] Change default SharedArea in SSHComputingElement
v6r10p23
Merge branch 'rel-v6r10' into rel-v6r11
Merge branch 'rel-v6r11' into integration