tls: force readable/writable to `true`

These are an old and deprecated properties that was used by previous
stream implementation, and are still in use in some user-land modules.

Prior to this commit, they were read from the underlying socket, which
may be non-readable/non-writable while connecting or while staying
uninitialized.

Force set them to `true`, just to make sure that there will be no
inconsistency.

fix #7152
tls: do not call SNICallback unless present

When asynchronously parsing ClientHello for session resumption -
SNICallback may not be set. Check if it is present before invoking
it.

fix #7010
deps: apply floating patch to v8

Original commit message below:

fix FunctionCallbackInfo ambiguity

- when compiling tools that embed v8 with g++ FunctionCallbackInfo is currently ambigous
- more info: https://github.com/joyent/node/issues/7337
- original patch is here: https://codereview.appspot.com/78770045/

TBR=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/201573012

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20217 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
http: better client "protocol not supported" error

Include the "expected protocol" in the Error message
string, which evaluates to "http:" for the `http`
core module, and "https:" for the `https` module.

Closes #7355.
configure: --v8-options option

Introduce a way to set some v8 flags at compile time, the values should
be separated by comma.
crypto: move `createCredentials` to tls

Move `createCredentials` to `tls` module and rename it to
`createSecureContext`. Make it use default values from `tls` module:
`DEFAULT_CIPHERS` and `DEFAULT_ECDH_CURVE`.

fix #7249