Makefile.am: add rules for htools compilation
Makefile.am: add rules for htools compilation

This patch adds some (not very nice) rules for htools
compilation. Since automake only knows about some languages, and
doesn't have a real extension mechanism, I cheat and declare them as
"buildable scripts", instead of programs. Rationale:

automake support for dir_PROGRAMS is limited to a few languages; in
all cases, it assumes that translation from sources to binaries occurs
in two steps, compilation and linking; it's not easy to change its
assumption.

In our case, where “ghc --make” does both steps, it's hard to force it
into the automake model.

Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Michael Hanselmann <68b67885ff74281219b4a4be33cc20fd45078d7c@google.com>

andir/ganeti,leshchevds/ganeti,leshchevds/ganeti,leshchevds/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti,yiannist/ganeti,andir/ganeti,yiannist/ganeti,ganeti/ganeti,mbakke/ganeti,ganeti-github-testing/ganeti-test-1,dimara/ganeti,dimara/ganeti,mbakke/ganeti,onponomarev/ganeti,andir/ganeti,apyrgio/ganeti,ganeti/ganeti,onponomarev/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,mbakke/ganeti,bitemyapp/ganeti,ganeti/ganeti,apyrgio/ganeti,grnet/snf-ganeti