Windows make install

[Mike Thomas]

Hi Simon.

| If Happy doesn't check its executable directory, where does it get the
| location of the templates from?

Happy - hard wired to "/usr/local/lib/happy" irrespective of platform.
Alex - the current working directory.
Haddock - won't proceed without a --lib/-l command line option.

I modified alex to search the executable directory (rather than the current
working directory) using code copied from ghc's "SysTools.lhs" and that was
OK.

I didn't check tha change in, as I couldn't get the C preprocessor to switch
windows code on/off (even with -cpp and -fglaswow-exts) and also because I
would not have been able to test the Unix variation.

Further, rather than replicating the code in the utilities as well as GHC
itself, maybe a "getExecutablePath()" function should be put into one of the
GHC or system libraries.  What say you?

Other than that, I checked in changes to use ".exe" on Windows or ".bin" on
Unix for Happy, Alex and Haddock.  Those utilites work fine out of the
installation target directory (which they cohabit with GHC and it's
sub-tools) under a Windows XP command prompt provided they are fed
their -t/-l command line options.

That install target directory should now be bundleable into a zip (or, I
suppose, msi) file and sent off to end users without further messing around.

Next week I may need to iron out some monsters with respect to greencard and
hdirect by investigating more closely the way in which the Makefiles work
out which utilities to install - it turns out that greencard install
autodetection is not working.  Hdirect makes it into the target directory,
but I haven't had time to give it a shakedown yet.

Then there is also the nightly build modification taking advantage of the
working Windows install. After that I think it should be OK to sit until we
get some user feedback on this stuff.

Cheers

Mike Thomas.