Patch #32: Updated Maven plugins and added versions at POM for plugins without version.
Patch #33: Updated JAR dependencies versions.
Patch #34: Built on Java 6.
Defect #27: Extension .64 doesn't work. Now it's changed to .base64. Tests added.
Defect #28: For resources called 'Signatures' the singular is not well made. Added an exception for signatures. Tests added.
Defect #29: Identifiers for resources didn't allow alphabet chars although the
identifier started with number. Changed to allow this kind of identifiers. Tests added.
Defect #30: GroupId for serfj must be net.sf.serfj instead of net.sf. Changed to net.sf.serfj.
Defect #31: When not serializer is found a NullPointerException is thrown.
Defect #35: NPE thrown when server is not reached.
