[BZ 1076126] - RFE: Canned dynaGroup expressions provided by plugin

Added concept of 'additional descriptor' (optional zml file living in
plugin's META-INF folder side-by-side to plugin descriptor). This file is
parsed only by server when plugin is discovered. Within this xml file, we
currently store predefined expressions for read dynaGroup definitions. Such
expressions can install dynaGroup definitions automatically. This commit
contains also logic which takes care about dynaGroupDefs created using such
expressions. When plugin updates such expression, dynaGroup is updated (same
for delete). GroupDefinition table has now "weak" reference to expression
(Plugin:ExprId)

Predefined dynaGroup expressions hardcoded in SingleGroupDefinitionView.java
have been replaced by cannedExpressions provided by plugins. From user
perspective, almost nothing changed, except cannedExpressions contain more
than just expression string, so when user selects template/expression fields
like name,description,recursive,recalcInterval are pre-populated as well.

Added 3 expressions. First groups managed servers by server-group name
(deploys DG) 2nd groups managed servers by hostname (aka domain) (deploys
DG) 3rd groups enabled deployments per server-groups

For expressions with 'createByDefault=true': dynagroups being created are
attached to plugin (having non-null cannedExpression). Whenever this
dynagroup is changed (via API or UI) it get's detached from plugin (setting
cannedExpression to null). Also on plugin upgrade or first install, if we
find a detached dynagroup having same name as we are about to create, we
just log INFO message - this happens when DG got previously detached.
[BZ 1076126] Update Group Definitions UI to show DGs from plugins

When listing dynaGroups we now show additional first column having an icon
of user - in case of regular dyna group or plugin - in case definition comes
from plugin. When user edits plugin-based definition we also warn him once
he attemts to save such expression. Within this commit i18n messages for old
template names has been removed.
bump dbversion
Merge pull request #11 from lzoubek/feature/canned-expressions

Bug 1076126 - RFE: Canned dynaGroup expressions provided by plugin