[GuidelinesChange] Prepping BuildRoot For %install

["Tom \"spot\" Callaway" <tcallawa redhat com>]

An additional item has been added to the Packaging/Guidelines (as a
subsection to BuildRoot): 

Prepping BuildRoot For %install
It is important to properly prepare the BuildRoot in the %install
section of your package before it is used. Every Fedora package MUST
have an %install section that begins with either: 

%install
rm -rf %{buildroot}

or 

%install
rm -rf $RPM_BUILD_ROOT

This is to ensure that the BuildRoot will be created fresh during the 
%install section. 

Also, the following has been added to Packaging/ReviewGuidelines: 

- MUST: At the beginning of %install, each package MUST run rm -rf
%{buildroot} (or $RPM_BUILD_ROOT). See Prepping BuildRoot For %install
for details. 

This change was approved by the Fedora Packaging Committee and ratified 
by FESCO.

~spot