Adjust the warning levels across the entire solution in order to tidy
up the build log.
Also remove the vestigial macro definition _USRDLL and add the missing
macro definition _CRT_SECURE_NO_WARNINGS.
This is a cherry-pick of commit 719705a2ab932a353748371c2e57f39ebc4bb8a3
from branch 'libpng18'.
The commit removes the three compile warning options from the individual project
files into the zlib.props globals (this should probably be renamed in 1.7). It
increases the warning level from 4 to All and adds a list of the warnings which
need to be turned off. This is semi-documentary; the intent is to tell users of
libpng which warnings have been examined and judged non-fixable at present.
The warning about structure padding *IS* fixable, but it is a signficant change
(moving structure members around). It is currently partially fixed in 1.7, but
only partially.
Signed-off-by: John Bowler <jbowler@acm.org>
by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old GCCs.)
ARM support is enabled by default in zlib.props (unsupported by Microsoft) and
ARM compilation is made possible by deleting the check for x86. The test programs
cannot be run because they are not signed.
