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/Layer2/Aerohive.pm

@@ -30,6 +30,7 @@
 package SNMP::Info::Layer2::Aerohive;
 
 use strict;
+use warnings;
 use Exporter;
 use SNMP::Info::Layer2;
 
@@ -107,13 +108,12 @@ sub os_ver {
     my $aerohive = shift;
     my $descr    = $aerohive->description();
 
-    if ( $descr =~ m/\bHiveOS\s(\d\.\w+)\b/ix ) {
+    if ( defined ($descr) && $descr =~ m/\bHiveOS\s(\d\.\w+)\b/ix ) {
         return $1;
     }
     return;
 }
 
-
 sub mac {
     my $aerohive = shift;
     my $ahmac = $aerohive->ah_mac();
@@ -137,12 +137,11 @@ sub mac {
     return $macs[0];
 }
 
-
 sub model {
     my $aerohive = shift;
     my $descr    = $aerohive->description();
 
-    if ( $descr =~ m/\b(?:Hive|)(AP\d+)\b/ix ) {
+    if ( defined ($descr) && $descr =~ m/\b(?:Hive|)(AP\d+)\b/ix ) {
         return $1;
     }
     return;
@@ -345,11 +344,6 @@ Eric Miller
 Provides abstraction to the configuration information obtainable from an
 Aerohive wireless Access Point through SNMP.
 
-For speed or debugging purposes you can call the subclass directly, but not
-after determining a more specific class using the method above.
-
- my $aerohive = new SNMP::Info::Layer2::Aerohive(...);
-
 =head2 Inherited Classes
 
 =over