iASL: Add mechanism to disable specific warnings/remarks.

New command line option, -vw<messageid>. also #pragma disable <messageid>.
ACPICA BZ 989. Chao Guan, Bob Moore.
Fix for _INI regression introduced in version 20130328.

This change fixes a problem introduced in 20130328 where _INI methods
are no longer executed properly because of a memory block that is not
initialized correctly.
ACPICA BZ 1016. Tomasz Nowicki <tomasz.nowicki@linaro.org>.