BEANS: fixed converting empty string to attribute value

- When converting string to attribute value convert
  empty string as null, in order to keep equality between
  Oracle and Postgres DB.

  This will also fix case, when attributes are passed in Candidate object.

- Fixed typos in exceptions texts.
Merge pull request #398 from zlamalp/emptyattr

BEANS: fixed converting empty string to attribute value
CLI: fixed creation of perun-cli.tar.gz

- Fixed creation of perun-cli.tar.gz archive from CLI sources, since
  version from November 2013 was copied to AFS on every build
  (because of wrong file name).

- Added execution mark (+x) to CLI commands, which missed it.
Merge pull request #400 from zlamalp/cli

CLI: fixed creation of perun-cli.tar.gz
UTILS: point to right JDK when generating javadoc

- When generating javadoc for RPC API use custom installation of JDK
Merge pull request #401 from zlamalp/rpc-javadoc

UTILS: point to right JDK when generating javadoc
Add rights for engine to call getAssignedServices

Engine/dispatcher needs this method for resolving ExecService-Facilty
pairs from audit message.
Fix permissions check in services

If target file is symlink, permissions is checked on linked file (not on
symlink itself)

Affected services: fs_home, k5login and passwd_scp
New model ResourceState

- added new class ResourceState
- added method getResourcesState
GUI: when creating Facility always pass backup list

- Pass content of "backup list" from list of Facilities when
  creating new Facility, since simple "list" might be empty/filtered.
Merge pull request #402 from zlamalp/gui

GUI: when creating Facility always pass backup list
Fix UF:D:defaultUnixGID module

attribute GR:D:isUnixGroup is no longer used. You can tell if group is
unix group according to G:D:unixGroupName-namespace - if it is set, the
group is unix group.
RPC: added getAllResourcesState method
Merge pull request #404 from zlamalp/resource

RPC: added getAllResourcesState method
GUI: first version of resources state tab

- New tab "Resources state" replaces "Facilities states"
  in VO management section.
- Listing all VOs resources including their services and their state.
- Added all necessary methods and object definitions.
- Some source formatting.
Merge pull request #405 from zlamalp/guires

GUI: first version of resources state tab