For this fix, we need to make sure that passing too-large inputs to
the evbuffer functions can't make us do bad things with the heap.
Also, lower the maximum chunk size to the lower of off_t, size_t maximum.
This is necessary since otherwise we could get into an infinite loop
if we make a chunk that 'misalign' cannot index into.
The clang compiler provided with macosx emits warnings like:
CC bufferevent.lo
clang: warning: argument unused during compilation: '-I .'
clang: warning: argument unused during compilation: '-I ./compat'
clang: warning: argument unused during compilation: '-I ./include'
clang: warning: argument unused during compilation: '-I ./include'
for each file being compiled. This generates a lot of noise during
compilation making it hard to see "real" errors. This patch mute
those warnings.
