add libssh.pc for pkg-config?

[Vic Lee <llyzs@xxxxxxx>]

Hi,

Does it make sense to add a libssh.pc file to support pkg-config in 0.4?

I think it's quite common to use pkg-config for library development
nowadays. Please refer to:

http://en.wikipedia.org/wiki/Pkg-config

This makes it much easier for projects checking for libssh, and it also
has native macro PKG_CHECK_MODULES for GNU make systems. And it does not
affect any other source codes - just an extra file install
in /usr/lib/pkgconfig.

Any comments?

Thanks,

Vic