SPRING: Fixed Spring version used in xsd URL

- Use version-less URL for Spring xsd validators.
- Set version 3.1 in manually added spring.handlers and spring.schemas.
- Removed many unused or duplicite context definitions.

Now correct mapping should be provided by Spring libraries, which maps
URLs to classpath.
Prepare usedGids mechanics

- add methods for loading entityless attribute value from DB with "for
  update"
- add new module for attribute entityless_def_usedGids
- rework group_def_unixGID_namespace and resource_def_unixGID_namespace
  to use usedGids attribute
- add simple tests
Fixed Maven plugin execution for Eclipse

- Added lifecycle mapping for serviceloader plugin.
Updated project info in pom.xml
Do not set versions on plugins and dependencies in child projects

...because they are inherited from main project pom.xml

- Removed ant-run maven plugin lifecycle mapping for Eclipse,
  since plugin is not used by any of our modules.
Fix method getEntitylessAttrValueForUpdate

- if entityless attribute with subject not exists, create new one by
  insert (with null value) and work with it
	- without that you won't be able to create DB lock (row must exist),
		which is purpose of this method

- add new private method creating entityless attribute with null values
Merge pull request #388 from zlamalp/eclipse

Update project pom.xml

- Added lifecycle mapping for serviceloader plugin (for Eclipse).
- Removed lifecycle mapping for ant-run plugin (for Eclipse). It's not used anymore.
- Removed explicit version definition in child pom.xml since versions are inherited from parent.
- Updated project info in main pom.xml.
Merge pull request #387 from zlamalp/spring

SPRING: Fixed Spring version used in xsd URL

- Use version-less URL for Spring xsd validators.
- Set version 3.1 in manually added spring.handlers and spring.schemas.
- Removed many unused or duplicite context definitions.