pgsql: Enable transforms modules to build and run with Mingw builds.

Enable transforms modules to build and run with Mingw builds.

These modules were all missing essential Windows scaffolding, including
resources files and descriptions, and links to the relevant library
import files. This latter item means that the modules can't be built
with pgxs on Windows, as we don't install the import files. If we ever
decide to install them this restriction could probably be removed.

Also, as with plperl we need to make sure that perl's CORE directory is
last on the include list, as on Windows it appears to contain some
headers with names that clash with names of some headers we include.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/f802c6ddba143bd88512b5fc34e84ae0b4883284

Modified Files
--------------
contrib/hstore_plperl/Makefile   |   15 ++++++++++++---
contrib/hstore_plpython/Makefile |    8 +++++++-
contrib/ltree_plpython/Makefile  |    8 +++++++-
3 files changed, 26 insertions(+), 5 deletions(-)