[pcp] Improving user experience when using Fedora RPM packages

[Tadej Janež]

Hi!

Currently, when a PCP user wants to setup a collector host on a Fedora
system, he would install the "pcp-collector" package, which is a
meta-package that makes sure that all the pcp-pmda-* packages are
installed on the system.

But when a user wants to enable a PMDA, he has to manually install the
required dependencies.

For example, to enable the nginx PMDA, a user has to manually install
the LWP::UserAgent Perl module.
Similarly, to enable the postgresql PMDA, a user has to manually install
the DBD::Pg Perl module.

Wouldn't it be great if we added appropriate "Requires" to pcp
subpackages so that users don't have to manually hunt for PMDAs'
dependencies?

Greetings,
Tadej