Upgrade curl for resolve wordpress upgrade to 3.7 issue

When we do upgrade from 3.6.x to 3.7 that encounter problem with below error message.

The WordPress.org certificate lists '*.wordpress.org' as it's Common name
 in the SSL cert, 'wordpress.org' is added as an extra domain in the SSL
 subjectAltName Extension, which explains why api.wordpress.org would work,
 but wordpress.org would fail.

After check URL http://web.archiveorange.com/archive/v/XZYvy9JytAk5SqOwgSUB to know that is CURL version too old occurred.

That need to upgrade Linux CURL version from curl-7.10 to 7.15, and then recompile php-5.3.21 and re-install new complied php. Finally, to restart httpd service. Now, the wordpress can on-line upgrade to 3.7 normally.

PS. When I upgrade CURL to 7.15 which request upgrading libssh2 to 2.0.18 because the CURL need api libssh2_sftp_readnb() supported.