skypopen: updating link to skype client in install.pl, now is http://mirrors.kernel.org/archlinux/community/os/i686/skype-oss-2.0.0.72-3-i686.pkg.tar.xz

switch_file_exists returns switch_status_t so you cannot assume it returns a true value since success is 0

Signed-off-by: Travis Cross <tc@traviscross.com>

Re-bootstrapping is needed after this change.  Previously CentOS 5
systems wouldn't build correctly without this file in tree, but we've
adjusted bootstrap to compensate.

This workaround makes the build work exactly as it did when libzrtp
was installed as a system library.  By default gcc ignores warnings
caused by system headers, so for the moment we'll continue to pretend
that libzrtp headers come from the system.

I hate this file; we need to do something about this.

Partially revert "fix libzrtp build"
commit 0b6023b2