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/C1900.pm

@@ -1,5 +1,4 @@
 # SNMP::Info::Layer2::C1900
-# $Id$
 #
 # Copyright (c) 2008 Max Baker changes from version 0.8 and beyond.
 #
@@ -33,6 +32,7 @@
 package SNMP::Info::Layer2::C1900;
 
 use strict;
+use warnings;
 use Exporter;
 use SNMP::Info::CDP;
 use SNMP::Info::CiscoStats;
@@ -311,11 +311,6 @@ Catalyst 1900 device through SNMP.  See SNMP::Info for full documentation
 
 Note that most of these devices only talk SNMP version 1, but not all.
 
-For speed or debugging purposes you can call the subclass directly, but not
-after determining a more specific class using the method above.
-
- my $c1900 = new SNMP::Info::Layer2::C1900(...);
-
 =head2 Inherited classes
 
 =over
@@ -342,8 +337,6 @@ after determining a more specific class using the method above.
 
 F<ESSWITCH-MIB> is included in the Version 1 MIBs from Cisco.
 
-They can be found at ftp://ftp.cisco.com/pub/mibs/v1/v1.tar.gz
-
 =back
 
 =head2 Inherited MIBs
@@ -386,7 +379,7 @@ the version from there.
 
 =item $c1900->vendor()
 
-Returns 'cisco' :)
+Returns 'cisco'
 
 =back
 
@@ -420,10 +413,6 @@ See L<SNMP::Info::CiscoConfig/"GLOBALS"> for details.
 
 See L<SNMP::Info::CiscoStpExtensions/"GLOBALS"> for details.
 
-=head2 Globals imported from SNMP::Info::CiscoAgg
-
-See L<SNMP::Info::CiscoAgg/"GLOBALS"> for details.
-
 =head2 Globals imported from SNMP::Info::Layer2
 
 See L<SNMP::Info::Layer2/"GLOBALS"> for details.