Refactor: Allow for better static analysis, fixing some GCC analyzer warnings.

Refactor: Allow for better static analysis, fixing some GCC analyzer warnings.

* gettext-tools/src/cldr-plural.y: Define SB_NO_APPENDF.
* gettext-tools/src/its.c: Likewise.
* gettext-tools/src/read-desktop.c: Likewise.
* gettext-tools/src/read-properties.c: Likewise.
* gettext-tools/src/x-awk.c: Likewise.
* gettext-tools/src/x-c.c: Likewise.
* gettext-tools/src/x-java.c: Likewise.
* gettext-tools/src/x-javascript.c: Likewise.
* gettext-tools/src/x-lua.c: Likewise.
* gettext-tools/src/x-perl.c: Likewise.
* gettext-tools/src/x-php.c: Likewise.
* gettext-tools/src/x-python.c: Likewise.
* gettext-tools/src/x-rst.c: Likewise.
* gettext-tools/src/x-smalltalk.c: Likewise.
* gettext-tools/src/x-vala.c: Likewise.
* gettext-tools/src/x-ycp.c: Likewise.