--libcurl: fix for non-zero default options

If the default value for an option taking a long as its value is non
zero, and it is set by zero by a command line option, then that command
line option is not reflected in --libcurl's output. This is because line
520-521 of tool_setopt.c look like:

if(!lval)
    skip = TRUE;

An example of a command-line option doing so is the -k option that sets
CURLOPT_SLL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST to 0L, when the
defaults are non-zero.
Merge remote-tracking branch 'bagder/master'
url.c: fix HTTP CONNECT tunnel establishment upon delayed response

Fixes initial proxy response being processed by the tunneled protocol
handler instead of the HTTP wrapper handler. This issue would trigger
upon delayed CONNECT response from the proxy.

Additionally fixes a multi interface code-path in which connections
would not time out properly.

This does not fix known bug #39.

URL: http://curl.haxx.se/mail/lib-2013-01/0191.html
always-multi: always use non-blocking internals

Remove internal separated behavior of the easy vs multi intercace.
curl_easy_perform() is now using the multi interface itself.

Several minor multi interface quirks and bugs have been fixed in the
process.

Much help with debugging this has been provided by: Yang Tse
RELEASE-NOTES: synced with c43127414d89
runtests.pl: make VPATH builds find valgrind.supp
RELEASE-NOTES: Added missing imap fix

Added missing imap fix as per commit 709b3506cd9b.
Merge remote-tracking branch 'bagder/master'