Making compatWarning less scary and misleading.

For example, a user of ldap:1.4 saw ldap:1.9 as an update and though this was a problem, when it is not.

core/src/main/resources/hudson/PluginManager/table.properties

@@ -20,8 +20,9 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 compatWarning=\
- Warning: New version not compatible with installed version. \
- Jobs using this plugin may need to be reconfigured.
+ Warning: the new version of this plugin claims to use a different settings format than the installed version. \
+ Jobs using this plugin may need to be reconfigured, and/or you may not be able to cleanly revert to the prior version without manually restoring old settings. \
+ Consult the plugin release notes for details.
 coreWarning=\
  Warning: This plugin is built for Jenkins {0} or newer. \
  It may or may not work in your Jenkins.
@@ -33,5 +34,5 @@ depCompatWarning=\
 depCoreWarning=\
  Warning: This plugin requires dependent plugins that are \
  built for Jenkins {0} or newer. The dependent plugins may \
- or may not work in your Jenkins and consenquently this \
+ or may not work in your Jenkins and consequently this \
  plugin may or may not work in your Jenkins.