Added method from program name functionality

More and more documentation point to the connect-proxy package when
users want to use git:// URLs with the "git" application behind a
firewall and a proxy. However, git has one problem: the core.gitProxy
setting (equivalent to ProxyCommand configuration option for ssh) can
only support the full path to the proxy command and doesn't support
parameters. While users can specify most of the command line
parameters via environment variables, the connection method must still
be specified via parameters (when users prefer other than DIRECT
connection).

Since connect.c already includes a functionality for cvs to specify
the port in the executable name (i.e. connect-25 host), this patch has
added a ability to parse the executable name and search for the
connection method, for example "connect-proxy-socks host port" will
connect via socks proxy because of the program name being suffixed
with the "-socks" string. Similarly, users can rename/symlink/copy the
connect executable as connect-http or connect-telnet, or even
connect-something-somethingelse-socks.

This functionality has the least priority and is applied only when no
connection method has been selected via command line parameters.

Signed-off-by: Alin Dobre <alin.m.dobre@intel.com>