Make tests `colon*.test' more "semantic".

Make tests `colon*.test' more "semantic".

Prefer running configure and make over grepping the generated
files; this is both more correct and less fragile.
* tests/colon.test: Made more "semantic", as described above.
* tests/colon5.test: Likewise.
* tests/colon6.test: Likewise.
* tests/colon7.test: Likewise.
* tests/colon2.test: Likewise, and improve syncing with sister
test `colon3.test'.
* tests/colon3.test: Likewise (but with the sister test being
`colon2.test' here).