[monitoring-plugin-perl] Remove "experimental" tag on "Message Methods"

[Tom Ryder]

 Module: monitoring-plugin-perl
 Branch: master
 Commit: 77de65e149c519f551e03e11c9c26605c9866b72
 Author: Tom Ryder <tom at sanctum.geek.nz>
   Date: Mon Mar  5 09:56:22 2018 +1300
    URL: https://www.monitoring-plugins.org/repositories/monitoring-plugin-perl/commit/?id=77de65e

Remove "experimental" tag on "Message Methods"

>From a maintainer, Sven Nierlein:
> I'd say we can remove the "experimental" tag there. It had been there
> for years now and i see no reason why we would change them.

Partly resolves #14.

---

 lib/Monitoring/Plugin.pm | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/lib/Monitoring/Plugin.pm b/lib/Monitoring/Plugin.pm
index 7e1c4d0..3052266 100644
--- a/lib/Monitoring/Plugin.pm
+++ b/lib/Monitoring/Plugin.pm
@@ -287,8 +287,7 @@ Icinga or Shinken (and compatible) plugins.
    );
    $np->plugin_exit( $code, "Threshold check failed" ) if $code != OK;
 
-
-   # Message methods (EXPERIMENTAL AND SUBJECT TO CHANGE) -
+   # Message methods
    #   add_message( CODE, $message ); check_messages()
    for (@collection) {
      if (m/Error/) {
@@ -580,8 +579,6 @@ need to do that from a plugin script.
 
 =head2 MESSAGE METHODS
 
-EXPERIMENTAL AND SUBJECT TO CHANGE
-
 add_messages and check_messages are higher-level convenience methods to add
 and then check a set of messages, returning an appropriate return code
 and/or result message. They are equivalent to maintaining a set of @critical,