pgsql: Turn install.bat into a pure one line wrapper fort he perl scrip

Turn install.bat into a pure one line wrapper fort he perl script.

Build.bat and vcregress.bat got similar treatment years ago. I'm not sure
why install.bat wasn't treated at the same time, but it seems like a good
idea anyway.

The immediate problem with the old install.bat was that it had quoting
issues, and wouldn't work if the target directory's name contained spaces.
This fixes that problem.

I committed this to master yesterday, this is a backpatch of the same for
all supported versions.

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/4dac5651b15ded7ce3b730aec936bec957b2c86a

Modified Files
--------------
src/tools/msvc/install.bat | 29 ++++-------------------------
src/tools/msvc/install.pl | 13 +++++++++++++
2 files changed, 17 insertions(+), 25 deletions(-)