Add RISKS section to Bash tools. Re-order all tools' DOWNLOADING section. Remove some unused options.

bin/pt-summary

@@ -1196,12 +1196,31 @@ tool works well on Linux systems.
 
 Download and run:
 
-   wget http://aspersa.googlecode.com/svn/trunk/summary
-   bash ./summary
+   wget http://percona.com/get/pt-summary
+   bash ./pt-summary
 
 Download and run in a single step:
 
-   wget -O- http://aspersa.googlecode.com/svn/trunk/summary | bash
+   wget -O- http://percona.com/get/summary | bash
+
+=head1 RISKS
+
+The following section is included to inform users about the potential risks,
+whether known or unknown, of using this tool.  The two main categories of risks
+are those created by the nature of the tool (e.g. read-only tools vs. read-write
+tools) and those created by bugs.
+
+pt-summary is a read-only tool.  It should be very low-risk.
+
+At the time of this release, we know of no bugs that could cause serious harm
+to users.
+
+The authoritative source for updated information is always the online issue
+tracking system.  Issues that affect this tool will be marked as such.  You can
+see a list of such issues at the following URL:
+L<http://www.percona.com/bugs/pt-summary>.
+
+See also L<"BUGS"> for more information on filing bugs and getting help.
 
 =head1 DESCRIPTION