Write a new autoconf macro to test whether a function is declared. It is suboptimal and possibly buggy in some way, but it seems to work for me. use it to test for a declaration of malloc_good_size, so we can workaround operating systems (like older OSX) that have the function in their libc but do not deign to declare it in their headers. Should resolve bug 587.
svn:r13339
Handle cross-compilation more sanely: avoid most uses of the (never-defined!) CROSS_COMPILE variable; in the one place where we cannot help it, use the correct cross_compiling.
svn:r12945
Do not alter CPPFLAGS until we are actually done with the rest of configure.in: this way, we notice if there are library paths that we are missing.
svn:r10345
More autoconf hacking: use same machinery to find zlib as for openssl and libevent. Have unified library finder include setup for --with variable. Start trying to suggest to the user what packages they should install if finding the library fails.
svn:r9945
Macro-ize our "search for a library and find out how to link against it" code. This will help make our handling of libevent and openssl more similar, and with any luck better. Not pushing to main branch until after 0.1.2.
svn:r9726
