OPTIM/MINOR: proxy: reduce struct proxy by 48 bytes on 64-bit archs

Just by moving a few struct members around, we can avoid 32-bit holes
between 64-bit pointers and shrink the struct size by 48 bytes. That's
not huge but that's for free, so let's do it.
MINOR: log: add a new field "%lc" to implement a per-frontend log counter

Sometimes it would be convenient to have a log counter so that from a log
server we know whether some logs were lost or not. The frontend's log counter
serves exactly this purpose. It's incremented each time a traffic log is
produced. If a log is disabled using "http-request set-log-level silent",
the counter will not be incremented. However, admin logs are not accounted
for. Also, if logs are filtered out before being sent to the server because
of a minimum level set on the log line, the counter will be increased anyway.

The counter is 32-bit, so it will wrap, but that's not an issue considering
that 4 billion logs are rarely in the same file, let alone close to each
other.
BUG/MEDIUM: http: fix inverted condition in pat_match_meth()

This results in a string-based HTTP method match returning true when
it doesn't match and conversely. This bug was reported by Joe Williams.

The fix must be backported to 1.5, though it still doesn't work because
of at least 3-4 other bugs in the long path which leads to building this
pattern list.