Cabal: Add snap-core dependency

It turns out that metad depends directly on it.

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>
Cabal: Fix ganeti version (we're now at 2.14)

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>
Makefile: Make TAGS use -package-id and macro flags

Makes sure that generating TAGS uses the same library versions
as the build itself.

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>
Makefile: Refactor -package-id and macro flags to HFLAGS

All places HFLAGS is used also included these flags, and they make
sense for all GHC invocations in our build.

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>
Makefile: Remove spurious HS_REGEX_PCRE flags

They were removed from configure.ac and replaced by the MIN_VERSION_*
flags which are now passed by default via HFLAGS.

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>
Makefile: Pass -hide-all-packages to GHC

We already pass GHC all `-package-id`s that it should use.

This change makes sure that it *only* uses those.

Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>