compilation warnings on Ubuntu 12.04.3 LTS

A user encountered the following compilation warnings building OpenSRF 2.2.1 on Ubuntu 12.04.3 LTS:

...
.deps/libosrf_json_la-utils.Tpo -c utils.c -fPIC -DPIC -o .libs/libosrf_json_la-utils.o
utils.c: In function 'set_proc_title':
utils.c:133:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:133:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c: In function 'stringisnum':
utils.c:697:8: warning: ignoring return value of 'strtol', declared with attribute warn_unused_result [-Wunused-result]
utils.c: In function 'daemonize':
utils.c:665:8: warning: ignoring return value of 'chdir', declared with attribute warn_unused_result [-Wunused-result]
utils.c:672:10: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result]
utils.c:673:10: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result]
utils.c:674:10: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result]

...
.deps/osrf_legacy_json.Tpo -c -o osrf_legacy_json.o osrf_legacy_json.c
osrf_legacy_json.c: In function ‘json_eat_comment’:
osrf_legacy_json.c:607:6: warning: variable ‘fourth_dash’ set but not used [-Wunused-but-set-variable]
osrf_legacy_json.c: In function ‘jsonObjectIteratorNext’:
osrf_legacy_json.c:836:5: warning: passing argument 3 of ‘makeNode’ discards ‘const’ qualifier from pointer target type [enabled by default]
osrf_legacy_json.c:808:24: note: expected ‘char *’ but argument is of type ‘const char *’
mv -f .deps/osrf_legacy_json.Tpo .deps/osrf_legacy_json.Po

…
srfsh.c: In function ‘process_request’:
srfsh.c:367:9: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result [-Wunused-result]

….
/osrf_http_translator.c: In function 'osrfHttpTranslatorParseRequest':
./osrf_http_translator.c:299:25: warning: passing argument 1 of 'free' discards 'const' qualifier from pointer target type [enabled by default]
/usr/include/stdlib.h:488:13: note: expected 'void *' but argument is of type 'const char *'

These are likely benign, but it would be best if the build were clean.

OpenSRF: 2.2.1 (and probably also master)