Added status command to reference implementation and REP. Here is an
example output over bzr, git, hg and svn subdirs:
$ rosenv status test3 --untracked
+N test3/bzr-test/ bar
M test3/bzr-test/ foo.txt
M test3/ias_common/CMakeLists.txt
A test3/ias_common/foogit
M test3/ias_common/stack.xml
M test3/geometry_tutorials/turtle_tf/CMakeLists.txt
A test3/geometry_tutorials/bla.hg
! test3/geometry_tutorials/stack.xml
? test3/geometry_tutorials/bar.txt
? test3/geometry_tutorials/foo.txt
? test3/test/common_msgs/CMakeLists.txt.rej
? test3/test/common_msgs/.rosinstall
? test3/test/common_msgs/CMakeLists.txt.orig
A test3/test/common_msgs/foosvn
M test3/test/common_msgs/CMakeLists.txt
A little confusing. Not sure whether it's worth bothering to unify the
looks a bit.