Update to 2.17.8.

• Check for use of OPT_XXX_OFF syntax to prevent false incorrect option usage assertions. [1]
• Remove now-obsolete warning about using :LU operators with make(1). [2]
• Fix the regex to prevent direct command use from hittin on lines like FOO_USES=... [3]

PR: 218260 [1]

		218325 [2]
		218672 [3]

Submitted by: jrm [2]
Reported by: rezny [2]