add strict validatation of GF_OPTION_TYPE_PATH option type.
add strict validatation of GF_OPTION_TYPE_PATH option type.

Make sure that users don't provide "../" in the path value in volume file,
which should be considered security issue.

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 141 (GF_OPTION_TYPE_PATH should check for presence of ".." in path)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=141

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster