documentation overhaul (#353)

* ident
* remove $Id$ tags from rcs software which has been retired
* make an effort to sync required mib docs with actual code
* sync even more docs with what code actually does
* some whitespace nits
* fixup example to use snmpv2 for all but the most ancient devices
* remove blurb to find more specific snmp::info classes for classes
  which alrdy are as specific as they can get (eg snmp::info::layer3::vmware
  doesn't need info on to find a specific module since there ain't none)
* rename all sub {vendor} strings to lowercase vendor, if cisco, juniper
  and arista can be lowercase, so can be all the rest.
* fix tests
* spread some use warnings around
* use $ instead of @
* remove defines that are included via parent classes
* use strict + warnings
* remove alrdy included modules
* add comma after last list item
* typos
* mibs are found in our mib repo, not on the cisco site
* documentation fixes

lib/SNMP/Info/Layer7.pm

@@ -31,6 +31,7 @@
 package SNMP::Info::Layer7;
 
 use strict;
+use warnings;
 use Exporter;
 use SNMP::Info;
 
@@ -116,7 +117,7 @@ Jeroen van Ingen
                           Debug       => 1,
                           DestHost    => 'myswitch',
                           Community   => 'public',
-                          Version     => 1
+                          Version     => 2
                         )
     or die "Can't connect to DestHost.\n";
 
@@ -165,9 +166,9 @@ after determining a more specific class using the method above.
 
 =back
 
-MIBs required for L<SNMP::Info/"Required MIBs">
+MIBs required for L<SNMP::Info/"REQUIREMENTS">
 
-See L<SNMP::Info/"Required MIBs"> for its MIB requirements.
+See L<SNMP::Info/"REQUIREMENTS"> for its MIB requirements.
 
 =head1 GLOBALS
 
@@ -190,7 +191,7 @@ C<sysObjectID>.
 
 =head2 Global Methods imported from SNMP::Info
 
-See documentation in L<SNMP::Info/"GLOBALS"> for details.
+See documentation in L<SNMP::Info/"USAGE"> for details.
 
 =head1 TABLE METHODS
 
@@ -209,6 +210,6 @@ Returns reference to the map between IID and physical Port.
 
 =head2 Table Methods imported from SNMP::Info
 
-See documentation in L<SNMP::Info/"TABLE METHODS"> for details.
+See documentation in L<SNMP::Info/"USAGE"> for details.
 
 =cut