C warnings: which merit cage-cleaning?

[James E Keenan]

Tonight I had occasion to grep for the C warnings generated while 
running 'make' for each of the whiteknight/io_cleanup1 and threads branches.

io_cleanup1:  http://nopaste.snit.ch/157224
threads:  http://nopaste.snit.ch/157225

IIRC, these were all-gcc builds.  An all-g++ build would have a 
different set of warnings.

Setting aside the warnings that appear in any particular branch, to what 
degree should we be concerned about these?  Which can be cage-cleaned?

(On the subject of 'switch missing default case' warnings, I found this 
page from Eclipse informative:  http://preview.tinyurl.com/c93cuep. 
Search for the section "On using \"default:\""

Thank you very much.
Jim Keenan