Fix for ID: 3378952 - Map collection to collection
Fix for ID: 3378952 - Map collection to collection branch (cleanup the code)
Fix for ID: 3378952 - Map collection to collection branch (JUnit test)
move protobuf support to plugin module. Future work: add module detector and executor + move proto classes to another maven module.
move dozer-proto classes to separate module
move moduling to spi
fix concurrency problems by using copy on write collections
fix and clean poms, upgrade dependencies versions
fix bug with mapping null values to proto object's fields
Merge branch 'master' into modules

Conflicts:
	core/pom.xml
	core/src/main/java/org/dozer/DozerInitializer.java
fix pom.xml after merge
Merge pull request #27 from foal/3378952

Fix for ID: 3378952 - Map collection to collection, custom collections and map->list mapping works now
Merge pull request #39 from Spikhalsky/modules

Move protobuf to separate module and bugfixes
Switching to Sonatype Nexus as Maven repo and artifact signing;
documentation fix;
extracting signing process into Maven profile;
additional project metadata;
fix Apache Maven POM for SLF4j badness

The whole point of the slf4j facade is to allow libraries
to NOT provide a logging implementation. When we provide
a hard coded logging implementation here, in this case,
slf4j-log4j12, we are doing the exact same thing that
is a problem with Spring Framework, e.g.

This forces everyone to exclude slf4j-log412 when they
do not want to use Log4j as the final logging
implementation.
Merge pull request #43 from jieryn/master

fix Apache Maven POM for SLF4j badness
Concept of internal DI approach;
Spring integration extracted to separate module;