Added another bunch of compiler warnings and fix code.

configure

@@ -235,9 +235,12 @@ EOF
 # Check for some compiler warning flags.
 #
 for f in all extra error shadow "format=2" missing-prototypes \
-	missing-declarations nested-externs \
+	missing-declarations nested-externs vla no-overlength-strings \
+	unsafe-loop-optimizations undef sign-compare format-security \
+	missing-include-dirs format-nonliteral old-style-definition \
+	init-self redundant-decls float-equal missing-noreturn \
 	cast-align cast-qual pointer-arith comment unused-macros \
-	declaration-after-statement stack-protector; do
+	declaration-after-statement write-strings stack-protector; do
 	check_compiler_flag ${f} W
 done