Set of changes so that "obtrusive" syntactic elements in a

Set of changes so that "obtrusive" syntactic elements in a
C/C++/ObjC preprocessor line (e.g. an unbalanced string quote or
unmatched paren) don't interact syntactically with stuff outside
the CPP line.
(c-basic-common-init): C and ObjC now use syntax-table text properties.
(c-common-init): Call language specific before/after-change functions at
mode initialisation.
(c-new-BEG, c-new-END, c-old-BOM, c-old-EOM): new variables.
(c-extend-region-for-CPP, c-neutralize-CPP-line,
c-neutralize-syntax-in-CPP): new functions.
(c-before-change, c-after-change): call the new language specific change
functions defined in cc-langs.el.
(c-advise-fl-for-region): new macro.
(awk-mode): Remove AWK specific stuff which has been refactored into
language independent stuff.