add support for building dbg debs separate from main packages

I worked on this inside catkin a while back.  The patch below is now way out of date, but should capture most of the issues.  

The old ticket was ros/catkin#20

A few notes from that ticket: 
semi official way to do it by debian is here: http://wiki.debian.org/DebugPackage of course it doesn't just work.

Ok, i've gotten it working in my fork. To do this correctly we should see if we can get cmake/catkin to produce the install files. http://manpages.ubuntu.com/manpages/natty/man1/dh_install.1.html  -- referring to the patch below. 

Old ticket in ros trac: https://code.ros.org/trac/ros/ticket/3365


```

From b6843f81421c0645a04c910e73ce79a4bff1b6b1 Mon Sep 17 00:00:00 2001
From: Tully Foote <tfoote@willowgarage.com>
Date: Sat, 11 Feb 2012 00:37:12 -0800
Subject: [PATCH] attempt to fix issue #20

---
 bin/catkin-generate-debian |    5 +++++
 bin/em/control.em          |    6 ++++++
 bin/em/package.install.em  |    1 +
 bin/em/rules.cmake.em      |    4 ++++
 4 files changed, 16 insertions(+)
 create mode 100644 bin/em/package.install.em

diff --git a/bin/catkin-generate-debian b/bin/catkin-generate-debian
index a1daf6d..753c6db 100755
--- a/bin/catkin-generate-debian
+++ b/bin/catkin-generate-debian
@@ -222,6 +222,11 @@ def generate_deb(stack_yaml, repo_path, stamp, debian_distro, rosdep_db):
     expand('changelog', stack_yaml, source_dir, dest_dir, filetype=stack_yaml['Catkin-ChangelogType'])
     expand('rules', stack_yaml, source_dir, dest_dir, filetype=stack_yaml['Catkin-DebRulesType'])
     expand('copyright', stack_yaml, source_dir, dest_dir, filetype=stack_yaml['Catkin-CopyrightType'])
+    try:
+        shutil.copyfile(os.path.join(source_dir, 'package.install.em'), os.path.join(dest_dir, '%s.install'%stack_yaml['Package']))
+    except Exception, ex:
+        print ("Failed to copy %s.rosintall into debian directory."%stack_yaml['Package'], ex)
+
 
     #compat to quiet warnings, 7 .. lucid
     ofilename = os.path.join(dest_dir, 'compat')
diff --git a/bin/em/control.em b/bin/em/control.em
index b95b13b..eed146d 100644
--- a/bin/em/control.em
+++ b/bin/em/control.em
@@ -10,3 +10,9 @@ Package: @(Package)
 Architecture: any
 Depends: ${shlibs:Depends}, ${misc:Depends}, @(','.join(DebDepends))
 Description: @(Description)
+
+Package: @(Package)-dbg
+Section: debug
+Architecture: any
+Depends: @(Package) (= ${binary:Version}), ${misc:Depends}
+Description: @(Description)
diff --git a/bin/em/package.install.em b/bin/em/package.install.em
new file mode 100644
index 0000000..a16cadd
--- /dev/null
+++ b/bin/em/package.install.em
@@ -0,0 +1 @@
+/opt/ros/fuerte
diff --git a/bin/em/rules.cmake.em b/bin/em/rules.cmake.em
index ee50aa2..9a9c44d 100755
--- a/bin/em/rules.cmake.em
+++ b/bin/em/rules.cmake.em
@@ -26,3 +26,7 @@ override_dh_auto_configure:
 override_dh_auto_test:
 	echo -- Running tests. Even if one of them fails the build is not canceled.
 	dh_auto_test || true
+
+
+override_dh_strip:
+        dh_strip --dbg-package=@(Package)-dbg
-- 
1.7.10
```