ship the apt-internal-solver in apt-utils package and link it to

/usr/lib/apt/solvers so we have it available for playing as 'apt'

debian/apt-utils.links

@@ -0,0 +1 @@
+usr/bin/apt-internal-solver usr/lib/apt/solvers/apt

debian/rules

@@ -62,7 +62,7 @@ configure.in:
 endif
 
 # APT Programs in apt-utils
-APT_UTILS=ftparchive sortpkgs extracttemplates
+APT_UTILS=ftparchive sortpkgs extracttemplates internal-solver
 
 # Uncomment this to turn on verbose mode.
 #export DH_VERBOSE=1