Previously, set_flags() would replace all previous user-visible flags.
Now it just sets the flags, and there is a clear_flags() function to
clear other flags.
svn:r1293
From the documentation:
Prevent calls that modify an evbuffer from succeeding. A buffer may
frozen at the front, at the back, or at both the front and the back.
If the front of a buffer is frozen, operations that drain data from
the front of the buffer, or that prepend data to the buffer, will
fail until it is unfrozen. If the back a buffer is frozen, operations
that append data from the buffer will fail until it is unfrozen.
We'll use this to ensure correctness on an evbuffer when we're waiting
for an overlapped IO call to finish.
svn:r1143
The old evbuffer_find didn't allow iterative searching, and forced us
to repack the buffer completely every time we searched in it. The
new evbuffer_search addresses both of these. As a side-effect, the
evbuffer_find implementation is now a little more efficient.
svn:r1130
