Remove hard-coded line number from templates.exp

templates.exp has a hard-coded line number in it:

  gdb_test "b 770" \
      "Breakpoint .* at .*, line 770."

The problems with this are well-known, and this patch simply removes it.
I've also added the missing FSF copyright header to templates.cc.

testsuite/ChangeLog:

	* gdb.cp/templates.cc (main): Add breakpoint marker comment.
	* gdb.cp/templates.exp: Remove hard-coded line number.